[tybee]

Dave,

In response to your comments about my description of synergy, I would like to offer a few thoughts.  When I refer to synergy, I am referring to how all of the components in a system interact together to optimize the sound reproduction for the listener.  For me, synergy not only includes the amp, preamp, CDP or turntable/arm/cartridge, but it also includes the speaker cable, interconnects, speaker stands, component racks, vacuum tube combinations, 1801 speakers and most importantly, the listening room.  For me, when all of the system components blend and work together correctly, the sound reproduction is wonderful. 

I continue to be amazed at how changing a tube or a speaker cable or power cable can change the character of the sound of the 1801s.  Like the tale of the three bears, the porridge is too hot, too cold, or just right.  I am finding that mating the right components together makes the sound to my ears, just right.  Often times, as many of us try to put together systems to satisfy our listening tastes, we put the wrong combinations together which results in frustration and Audiogon sales.  For me, the 1801s have many sonic strengths that certain components can help reveal.  As I previously mentioned, I love tube equipment with the 1801s.  Bill Baker has provided a great amp and Mark Deneen of Juicymusic has given me a great preamp with built in phono.  Nathan Loyer of Eighth Nerve not only provided me excellent acoustical room treatment, he has also created some excellent power cables and isolation components (Nerve Endings).  Chris Futrick of Solidwood has created my custom wooden 1801 speaker stands and rack shelving.  Greg Staley of Reality Cables makes an excellent speaker cable and Kevin Haskins of DIY Cable has provided me some excellent ICs as well as a custom phono cable for my Grace 707 tonearm. 

My past attempts at finding suitable components to work with the 1801s were a failure.  I suspect many who have given up on the 1801s did not find that right combination of components to satisfy their listening tastes.  This ongoing thread is important for the satisfied 1801 users to share with others the positive experiences with amplification as well as other system components that work well together with the 1801s.  I know you have tried to overcome the fear of many that a 30 watt tube amp is not enough power for the 1801s.  As I have previously posted, I have used an 8 watt Eastern Electric tube amp with my 1801s with success.  Granted the 8 watter did not have the headroom of my Response Audio 50 watter, but the 8 watter did not embarrass itself.  The little EE tube amp did drive my 1801s and sounded decent, but I would not recommend this amp for everyday use with the 1801s.  It is better suited for single driver speakers offered by other fine vendors who offer products here.

Let me end this long response by saying the 1801s have recently provide me some sonic magic that I have been missing for awhile.  Mrs. Tybee, who has better ears than me, says the 1801s in my current configuration scores her vote as a keeper.

[teiki arii]

For a very low price and quite good quality, I can tell you that Flying Mole DAD-M100proHT are astonishing for their price. I actually don't like at all the "class D ampli" -nuforce and Jeff rowland with ice power from B&O-, but these ones are wonderful and a bargain. No need to spend too much money for a very good system. It works very well with a lot of speakers: Ellis 1801b including the Revel Studio Ultima...
I have compared my system with McIntosh C26/MC7270...
I use a Vecteur L4.2 OAD, an optimized cayin Preampli SC-6LS OAD (Telefunken "Diamond" ECC83 smooth plates, Mullard BVA CV4003/M8136 "shield" box plates/ RTC E80CC) with two Flying Mole DAD-M100proHT monoblocks OAD and Ellis 1801b OAD...
the modded Cayin preamp SC-6LS OAD (the tubes are not the now ones):

[rez]

Just finished and plugged in my 1801b's for the first time tonight.  Just couldn't stop listening - including stuff I hadn't listened to in a while and these speakers are just magic.  Also, I found the Greg Ball 150D was outstanding with my previous speakers, Celestion SL6s's, but the matchup with the 1801b's is just sublime.

[amplifierguru]

Hi Rez,

Nice to see you've struck a synergistic combo with the 1801b's and my GB150D amps.  (synergy makes 3)

You are very astute with your upgrades and DIY +ve. 

Cheers,
Greg

[David Ellis]

My past attempts at finding suitable components to work with the 1801s were a failure.

Yep, source gear does have a very significant impact.  This is the reason I want to foster active discussion in this forum.  It's in my very selfish best interest to have my customers use good source gear.  It ensures the customer obtains the very best sound from the 1801.

The other very significant area of concern are recordings.  A fairly common response from 1801 customers is their realization that recording quality varies significantly.  The bad recordings are clearly obvious simply because the quality of the good recordings are sooooo good. 

I think (??) the listener can hear some commonality between distortions on the bad recordings and the distortions present from source gear.  I can't say this for sure, but it could be the case.  What surely cures both ailments is better source gear and better recordings.  Both of these are quite rare.

Dave

[David Ellis]

Also, I found the Greg Ball 150D was outstanding with my previous speakers,

Nice to see you've struck a synergistic combo with the 1801b's and my GB150D amps.

This is the 2nd person to convey exuberantly positive results with the GB150 amp.  I have heard nothing contrary.  Thanks for your contributions Greg!

I do have a question for Greg or rez.  Is it most common for folks to run the GB150 in Class A mode at 50wpc?  I think this would be plenty of power, but am uncertain what most folks are implementing.

Dave

[amplifierguru]

Hi Dave,

It is coming up to a year on Friday since the first GB150D amplifier kit was shipped. The amplifier was designed as a versatile topology which could be configured as Class AB or Class A and AC or DC coupled. Only a handful have been set up as Class A and with one notable Class A only exception (hi Jacco), all others have reverted to Class AB use - primarily to take advantage of the great headroom in 150W mode and no tangible loss of sonics over Class A operation.

This is as intended - I have deliberately targeted what I believe to be the main source of loss of sonic purity in Class AB - power supply artefacts, and virtually eliminated them, within the unique yet simple amplifier topology. This has the huge advantage over conventional approaches of being simple, compact, easy to build and needing a smaller power supply resource to achieve standout sonic results.

For those willing to take on the challenge of building this DIY amplifier, and Rez is one, a first timer I believe, who have been absolutely transfixed with the sonic result.

There certainly appears to be a synergy with the 1801b's that others have found - which I  have yet to experience!!

Cheers,
Greg

[David Ellis]

I received Steve Harrison's AKSA Lifeforce 55 a couple weeks ago.  I haven't performed a solid a/b versus my very Modified Golden tube SE40SE yet, but my  initial reactions for the AKSA Lifeforce are thus.

Yep, the AKSA Lifeforce is superior to the 55 Nirvana + and Superior to the Ultimate 70.  The midrange and highs have suprising depth and detail while never sounding harsh.  Eventually I'll get around to performing a solid comparison between the Lifeforce and the SE40SE.  I also hope to get a comparison with a friends OTL amp.  For now, my initial reaction is that the Lifeforce is an extremely capable world class amplifier.

It's also my unconfirmed observation this amplifier has some very good hand picked parts on the Circuit board.   The capacitors are all "boutique" units, and not all the same flavor.  Certainly electrolytic capacitors have a different sound character, and I believe Hugh has tediously selected the right capacitor its appropriate duty.  I believe this is at least part of the "magic" in the Lifeforce amplifier.  Of course, there are many who believe that all electrolytic capacitors sound the same.  Hopefully some exposure to the Lifeforce amplifier will convince these folks otherwise. 

Dave

[David Ellis]

I have used an 8 watt Eastern Electric tube amp with my 1801s with success. 

Is this the specific amplifier you tried?

http://www.tnt-audio.com/ampli/minimax_pwr_e.html

Several years ago I heard a Pilot 240 tube amplifier with a push/pull El84 setup that sound amazingly strong.  The speakers used were an 85db 2-way having @ 8db sensitivity.   This was my first exposure to lower powered tube amplifiers.  I enjoyed it, and it sounded darn good!  My second exposure immediately followed. 

It was a SET 8wpc 300b Cary.  It sounded bad.  It was awfully thin, and was a bit gritty.  The only thing it did well was place a saxophone precisely in the imaging soundstage.  The image was located high and to the left.  Aside from this, the 300b SET Cary with these 85db speakers was a loser.

My hunch is that amplifier stability is a significant factor when pushed, and the 300b Carywould do much better with a more sensitive speaker having a flat impedance.

Dave


Dave

[stvnharr]

I received Steve Harrison's AKSA Lifeforce 55 a couple weeks ago.  I haven't performed a solid a/b versus my very Modified Golden tube SE40SE yet, but my  initial reactions for the AKSA Lifeforce are thus.

Yep, the AKSA Lifeforce is superior to the 55 Nirvana + and Superior to the Ultimate 70.  The midrange and highs have suprising depth and detail while never sounding harsh.  Eventually I'll get around to performing a solid comparison between the Lifeforce and the SE40SE.  I also hope to get a comparison with a friends OTL amp.  For now, my initial reaction is that the Lifeforce is an extremely capable world class amplifier.

It's also my unconfirmed observation this amplifier has some very good hand picked parts on the Circuit board.   The capacitors are all "boutique" units, and not all the same flavor.  Certainly electrolytic capacitors have a different sound character, and I believe Hugh has tediously selected the right capacitor its appropriate duty.  I believe this is at least part of the "magic" in the Lifeforce amplifier.  Of course, there are many who believe that all electrolytic capacitors sound the same.  Hopefully some exposure to the Lifeforce amplifier will convince these folks otherwise. 

Dave

Hello everyone,
Aksa owner here.  I think I might like to add a few comments about my two amplifiers.  The Aksa Nirvana amp that I loaned to David a couple years ago was a Nirvana spec Aksa 55 with some blackgate caps and a few other parts changes, but was not a Nirvana Plus spec amp, as that specification did not exist at that time.  After receiving the amp back from David, I continued the modification process to full Nirvana Plus specification, and did some other changes as well.  My highly modified Nirvana that David listened to for those months was fairly close to the N+ final version, but not all the way there.  Small point perhaps, but I would like to note it.

The LifeForce 55 that is now on loan, is a completely stock amplifier module, with all stock parts in the amp module board.  However, the configuration is not as a straight stereo amplifier.  The amp is configured as a complete dual mono amplifier, complete with signal attenuators, series stepped attenuators to be exact, on each channel.  Thus, there is no need for a preamplifier in the system.  This is not the stock version that will be released by Aspen Amplifiers, when that comes to pass.

The LifeForce amp module is essentially a redesign of the original Aksa amplifier circuit.  It shares many of the original design concepts and sound with the original Aksa amp, but does have some significant differences.  The LifeForce has no H2 or H3 designed into it, and is very neutral in sound character, a technical design difference.  The bass performance of the amp is significantly improved from the Aksa amplifier, and there are other sound differences as well. 

There is now a user review of the LifeForce 100 at Critics Circle that was posted just a week ago.  There are several user reviews of LF55 and LF100 on the Aspen circle under the thread title, Listening Impressions and Listening Impressions II.

[smithy666]

I am using two Giovanni Stochino ultra fast amps as published in Electronics World. I have been using these on a pair of Dynaudio Finale speakers for the last 5 years or so. They are 100W amps slewing at 300V/us with very low distortion. I like their sound very much and always enjoyed listening to the Dynausios through them. Source in a Gryphon Tabu CD player through the Elektor battery powered pre-amp.

[David Ellis]

I have some... bad news.  I have invested too much money in my Golden Tube SE40SE (about $2400 total).  It has slight/pleasant tube-like sound and very good detail, but, it's inferior to the AKSA LF55.

Yesterday I conducted the official listening test with Mrs. Ellis, and she confirmed greater detail, layering, depth of soundstage, and bass resolution when using the AKSA LifeForce 55wpc amplifier.  The difference wasn't monumental, but it was present, and I agreed wit my wife's comments.  She doesn't speak "Stereophile", but the words that kept coming up were, "Yep, this one is better".  She would then explain why this was true from varying aspects.  The summation is that the LF55 is indeed a marginally better amplifier than my heavily modified Golden Tube SE40SE. 

I really don't know what Hugh did inside this amplifier.  My guess is the parts quality is a consideration and indeed the capacitors are all top-notch stuff.

Congratulations to Hugh Dean for making an incredibly good amplifier.  I didn't think this would happen, but it did.

There are several afore mentioned products that I have not auditioned/experienced.  The current hierarchy list is:

1.  AKSA LF55/LF100
2.  Golden Tube SE40 Modified by Jeff Glowacki at www.soniccraft.com
3.  VanAlstine Ultimate 70 (2 years old).
4.  Jolida 302b - modified

I will also offer some comment herein regarding the common commercial amplifiers.  The short summary is... the best quality parts are necessary to obtain the best possible results.  There are many good amplifiers on the market with fancy marketing campaigns touting their circuit typology.  While this matters (i.e. the Levinson 33 massive regulated power supply), the very best sound quality WILL ALWAYS  be obtained when using the best possible components internally.  Specifically, electrolytic capacitors with labels "Black Gate" (by Rubycon), "Elna Cerafine", "Nichicon Gold" are arguably the best possible components.  Coupling capacitors in tube circuits with labels "AudioCap Theta", "Sonicap", "AuriCap", "Jensen", "Mundorf Silver/Oil" etc. etc. .  There are certainly better quality diodes too.  It is worthwhile to note that high quality components will cost 10x to 20x more than "standard" components.  This is why 99.9% of hifi amplifiers don't use them... and remain inferior. 

This assertion is a generalization that assumes equally competent amplifier designs, design goals, and quality control.  I believe it is well within the reach of most amplifier designers to build a great amplifier using high quality components.  I do NOT believe it is within the reach of the accounting department to build a great amplifier using high quality (i.e. expensive) components.  Typology matters, but parts quality IS significant.  Given the same typology, an amplifier with better components will indeed sound better.

Dave

[hubert]

I really don't know what Hugh did inside this amplifier.

Somebody said me that, at least, he removed something but I'm sure he will explain it himself...

Typology matters, but parts quality IS significant.  Given the same typology, an amplifier with better components will indeed sound better.

Indeed, topology IS the important thing, as it is for speakers. I prefer average priced caps on a 1801 than silver/gold on...some other speakers aa

[David Ellis]

This is becoming a "can of worms".

Indeed, topology IS the important thing, as it is for speakers.

I... think that perhaps I need to clarify my opinion on this matter.  I agree that typology is important, but Typology isn't the only important element.  I believe this is valid for amplifiers and speakers.

I remain convinced that an optimized typology for a loudspeaker crossover is essential to the good results.  I would much rather have mediocre component quality with a well optimized crossover typology than great quality components with a poorly implemented typology.  My very first DIY speaker kit used a SEAS T25-001 tweeter and a Scanspeak 8545 midwoofer and it sounded terrible - until a gracious gentlemen redesigned the crossover. Then... oh, my!!  It was wonderful!

When I started in this hobby 7 years ago there weren't many folks capable of creating an extremely good loudspeaker crossover in the DIY realm.   Dennis Murphy, John K, Phil Bamberg, Geoffrey Dillon and George Short were very capable.  Certainly Mr. D'Appolito and  Mr. Linkwitz were capable on the commercial front too.  I heard a very solid rumor that many commercial folks were using a modeled crossover (not rigorously tested) in their commercial speakers (more on this later).  There were certainly other capable folks but not too many of them. 

Today there are many more solid designers.  Heck, I met a young guy named Chris D'Allesio (spelling?) that did very good work. Also, Scott Sehlin is solid, and so is Curt Campbell.  There are also the Packer fans; Scott, Nate and Matt.  And... Mike Bengfort.  All of these guys are very capable grass-roots DIY guys, and this is just in the Midwest region.  And... Dave Ellis managed a "quickie" crossover using the Accuton C95 and OW1 in about 4 hours that was on par with the 1801. 

I don't intend to infer that obtaining an optimized crossover is something that could be done in a weekend by a rookie with some modeling software.  My effort follows, oh, @ 6000 hours of reading and testing.  Other folks are surely smarter and are able to climb the learning curve quicker.  I do intend to infer that many folks are capable of good typology.

I believe this is true among speaker guys and amplifier guys. 

The only caveat I will offer (and repeat) is that a few amplifier typology issues are VERY complex.  As mentioned previously, the fully regulated power supply in the very expensive Levinson is profound.

After obtaining good typology, parts quality will provide that extra 10% of performance that is so difficult to obtain.  It can also be detrimental.  Many electrolytic capacitors are labeled with 10-20% tolerance because this is a reality for many components made in China.  IME any decent capacitor will be @2% tolerance.  And, this is on the obvious measurable differences.

Hererin I will offer some questions on the fringe of my knowledge that I believe impact manufacturing quality.  I don't have the answers to these questions in the amplifier realm and some of them may be a non-issue.  Nonetheless, I believe many of these have substance for amplifiers and loudspeaker crossover components. 

What happens when the film used in a poly capacitor becomes a bit thin/porous? What happens when the chemistry of the film changes from 1 roll to the next.  What happens when the metalized material crystallizes at a different rated due to ambient temperature variation?  What happens when the spray nozzle depositing the metalized material becomes partially clogged.  Why aren't all capacitors annealed.  Is all end-spray the same?  Are there more quality control problem areas????

In the speaker realm...

Are all voice coils perfectly centered in production run?  Do all surrounds have the same chemistry?  Are all surrounds the same thickness? Do all tweeter domes have ideally dispersed coating material?  Are all paper cones the same mass?  Are all voice coils concentric?  Are driver motor tolerances always consistent?  Are all top plate and pole piece assemblies precisely machined?

The answer to all of the speaker questions is mostly "no" - in varying degrees of extremity.  Some folks do an extremely good job with these things.  Other folks have, ahem,  less than ideal results.

My point in rambling, and am rambling, is that loudspeaker/amplifier research & development and the brilliant implementation by engineers when building a component is most often NOT commensurate with the end result.  The board members and accountants must realize a profit, and this often necessitates the use of inexpensive components and their commensurate quality.

Indeed, topology IS the important thing, as it is for speakers. I prefer average priced caps on a 1801 than silver/gold on...some other speakers

Primarily, the focus of this string is amplifiers, not speakers.

I believe amplifiers are much more sensitive to component quality than loudspeakers. This assertion has significant room for interpretation... so I'll clarify one aspect.

Upgrading from a Solen Capacitor to a Sonicap behind the tweeter of the 1801 is modestly audible.  After living with them for several years, I will always use a Sonicap.  However, I can easily understand that folks may wish to use the solen or something similar.  It has a touch more grit, and some folks may prefer this.  It adds splash and sizzle. Also, I think the use of a Mundorf Silver/Oil is completely unwarranted in a tweeter circuit. 

Upgrading from a Solen Capacitor to a Sonicap in a coupling circuit of a tube amp is significantly audible.  This upgrade was earth-moving for me when first accomplished in my CD player.

IMO, using a good quality coupling capacitor has 5x more impact than using a good quality tweeter capacitor.

I also feel it's somewhat fair "evidence" to use the results of the folks on the AKSA forum who upgraded their AKSA amps to Nirvana + versions and their results.  All commentary on this matter is extremely positive.  Better components DO matter.

In summary, I believe many folks can obtain a very good typology and this remains absolutely necessary.  After this, the quality of the components used is decisive.

Dave

[David Ellis]

I received this applicable query today:

Dave. While I have you here; wanted to ask you about the Aspen LF55 amp that you had a chance to hear, I saw your post on their web site. Did you try it with your 1801's? My next project is looking into replacing my old Crown DC300a amp and the LF55 sounds like a no brainer, providing you have the money for it. I saw on your web site that you said that you are cheap, well, I think I am cheaper. How did you like it and was there anything else out there you would recommend in place of it? The LF100 may be a little to hi in price for me. Wanted to know if you found the 55 powerful enough. What can you add to this? Ed

I did indeed use the LF55 with the 1801 and it has plenty of power.  This is true with all good @60wpc SS amplifiers. This continues to be my sentiment regarding the necessary power to drive the 1801 speaker to full spl.

I really don't understand the intimate issues regarding power ratings, sound quality, and commercial grade amplifiers.  It seems VERY prevalent that many of these amplifiers had something very strange happening with their power ratings.  It seems they are very generous/exaggerated.  The result is that many of these amplifiers can't manage to push clean power with the same finesse as a better quality hifi amplifier having the same power rating.  This was very true when using a comparison between my Bryston 3B-ST (120wpc), Jolida 302b (35wpc), and stereo Kenwood 126  (125wpc).   The Kenwood seemed to clip at the same spl or slightly lower spl than the Jolida.  The Bryston was a powerhouse of an amplifier when compared to the wimpy Kenwood having approximately the same power rating.  This is surely strange, but I can't avoid the reality of this situation. 

Many gents have conveyed that higher wattage commercial grade amplifiers simply sound better than the lower wattage commercial grade amplifiers.  I certainly will not dismiss their sentiment regarding commercial grade amplifiers.  I do believe there is truth in their comments, but cannot objectively explain why.  I only know that among better quality amplifers that @35wpc push pull tube (i.e. El34) or @60wpc SS is enough for the 1801. 

I continue to be cheap, but my amplifiers are much better than in the past. The LF amplifiers are getting expensive.  Spending less will net lesser sound quality, but can certainly result in a very decent sounding amplifier.  I truly don't have a sonically alternative to convey that is less expensive.   I have certainly experimented with a few things, and had a fair amount of feedback from my customers.  If you want to spend less, I recommend the Nirvana + 100wpc amp.  I do realize this sends up a red flag when contrasted against my previous commentary regarding power ratings, but I believe there is something strangely different and better in the Nirvana + 100wpc amp than extant in the 55wpc unit.  I can't explain this, and haven't accomplished a solid a/b test.  However, a faithful speaker-geek cohort did this test, and provided clear feedback on the matter.  I have also experienced both amplifiers in my system, but there was a significant time disparity.

If you want to experiment with something inexpensive, buy a Jolida 302b.  The only Achilles-heel is this amp eats the more fragile Svetlana EL34 tubes at a rate of 1 every 4 months (in my living room).  Nonetheless, it's a very decent amplifier from the factory and can become extremely good with some soldering.

If you want to experiment on the super cheap, I recommend a used Jolida 202a or Pilot 232 or Pilot 240 tube amp.  These amps will have enough juice for comfortably loud listening, but won't push the 1801 to its limit.  It seems the Pilot 232 has become more popular in recent years and the prices are rising.  I have a hunch these old amplifiers had very good transformers.

Dave

[David Ellis]

I forgot to mention something in my post above.

Most of the Crown amps seems to have an input impedance that is quite low - about 10k ohms.  Most hifi amps and most preamps are 50k ohms.  Higher impedance amps are a much easier load to drive with via CD player and passive preamp.  With a low impedance load, the need for an active preamp.  So, my swapping to an amplifier with a @50k ohm input impedance, you may be able to use very simple circuitry for the preamp - passive.

However, this is largely dependent on the CD player.  I have heard some CD players that really needed an active preamp - even with a 100k ohm amplifier. 

So, this is something that needs to be tested via system synergy and experimentation.

Dave

[jipper]

I will be using a Bottlehead Foreplay III preamp and a Dynaco st70 (ARC C3 mod) to drive a soon to be purchased set of speakers. the Ultimate 70 appears to be wonderful performer with ellis 1801s.  But it is usually only the higher volume levels that are covered by descriptions in this post.  For example, I have read lots of "will my XXX amp push enough sound pressure through my 1801 speakers to make me happy (and disturb my neighbours)".  It is clear now that an st70 with 35wpc will handle the 1801b very well in an average to small listening room. And the sound should be rather wonderful.

But, can someone please tell me more about listening to your 1801 and ultimate 70 combination:
at low volume levels?
how would you describe the sound-floor?
can the amp and speaker combination deliver adequate low-level sound reproduction?
(I do not mean bass, I mean can you hear pages being turned on the music stand in the back row)
and the detailing at softer listening levels?
do you enjoy your system completely at moderate listening levels, with as little fatigue as possible?
do you feel connected to the music before turning the volume up to chest-thumping levels.

Hope my questions are clear enough.  I have older and wiser neighbours who do not like loud listening levels and in fact I do not prefer them either.  I most prefer to hear all the music on a recording in a dynamic presentation at moderate levels. 

thanks very much for all of your replies.


J.P.

[David Ellis]

The Bottlehead Preamp...

I had the opportunity to audition an earlier version of the bottlehead preamp several years ago.  This version was Version 1, and had all the bells-and-whistles.  There were no further bottlehead mods/additions that could be performed on this preamp from the bottlehead providers.  It was the full cascode with Auricap coupling capacitors.  The cost of parts was about $475 with the stepped attenuators.  For testing, the bottlehead preamp replaced my Creek Passive preamp between my Anthem CD-1 and Bryston 3B-ST.

Candidly, I didn't like the Bottlehead preamp .  My wife agreed.  It sounded very fat, warm, mushy and round.  A fair amount of the detail present in the recordings was absorbed by the bottlehead preamp .  I can easily see where this preamp might have a keen advantage in some systems having considerable Solid-State hash (caused by many factors), but my system was okay in this regard.  I didn't need the "filtering" of the bottlehead preamp to hide anything in my system.

However, I have not followed the Bottlehead progression. They are obviously on Stage III, and some changes have occurred.  They might have fixed the problems present with the earlier preamps.  I really don't know .  I suggest following the rhetoric on this issue.  If the propensity of the rhetoric from folks experimenting with old and new variants of the Bottlehead preamp include commentary such as, "much cleaner, more dynamic, I can hear the strings etc. etc." - okay, great!  However, if those commenting convey, " warm, lush, smooth etc. etc. " - uh, I don't recommend this product.

I do think the warm, lush, smooth, fat sound of the original Bottlehead preamp creates a very retro sound that many people may appreciate.  Certainly it made my system sound very similar to an experiment where I implemented an old EL84 console radio 15wpc power amp in my system.  It sounded very warm, lush, smooth and fat.

I do suggest using a passive preamp.  Most variants of the Dynaco amplifier have a very high input impedance that will be very "friendly" to your CD player.  Specifically, I highly suggest using the standard Scott Endler stepped attenuators that will plug directly into the front of your Dynaco. This is what I use and I think they are just dandy  aa .  And, they do sound better than a standard-grade volume pot.  They look really cheap, but their performance is striking  .

My commentary on amplifiers in the previous pages and the hierarchical ratings is based on how they sound at perhaps 2 watts (average) of dissipation at the loudspeaker terminals.  The peaks vary based on music content, but listening is indeed at a very low level.  I rarely listen at chest thumping levels.  I won't get into stereophile rhetoric beyond what I have already commented previously in this discussion string.  All of my comparisons and previously mentioned hierarchy consider noise floor, clarity, dynamics, tonal quality, and instrumental balance.  Further, thick commentary would be of little use since you will be using a different version of the ST70.

how would you describe the sound-floor?

Not as dead as my Golden Tube SE40SE, but nonetheless VERY quiet.

can the amp and speaker combination deliver adequate low-level sound reproduction?(I do not mean bass, I mean can you hear pages being turned on the music stand in the back row)
and the detailing at softer listening levels?

Definitely!

do you enjoy your system completely at moderate listening levels, with as little fatigue as possible?

Again - Definitely!

do you feel connected to the music before turning the volume up to chest-thumping levels.

And again - Definitely!

I don't know anything about the ARC C3 mod for the Dynaco ST70.  It may be very competent, but I have never heard or read anything about it.  My only additional input on the matter is this:

1.  A local hifi enthusiast recently compared my Ultimate 70 to his slightly modified(not ARC C3) Dynaco ST-70.  He decided to sell his Dynaco ST-70 - enough said.

2.  Frank VanAlstine wrote some very good commentary about the original flaws in the Dynaco ST-70.  I believe most of them are here: http://www.avahifi.com/root/equipment/amplifier/70_rebuild_plans.htm  Specifically, the portions of his commentary addressing the need for the ST70 to "choke-down" the bass from the feedback circuit seem very applicable.  I don't know if all Dynaco mods address this issue, but I do believe this issue is very valid.

3.  There are MANY iterations of the Williamson push-pull amplifier present, and most seems to use the EL34 tube.  There is good reason for this.  The El34 is a very nice sounding tube (I prefer the common Svetlana C logo version), and will push enough juice for most folks in their home hifi system.   As such, I think believe your pursuit of of a modified Dynaco ST70 is very wise  .

Dave

[David Ellis]

Jipper,

Do you have a link for the ARC C3 Dynaco mods?

[jipper]

Sheepisly, I admit that I had very little reference to go on with this purchase (the audio research C3 mod ST70).  I read a great deal about the standard st70.  I read about the various other mods I could find details about.  And as I am just beginning in the "how to design an amplifier", some of the information about what each modification accomplished was not completely understood. The few pages where I could find (no handy list of pages) some mention of the C3 mod were all very favourable.  I thought any Dynaco would be a good place to start my own learning.

So, I don't have a place to point you towards for more information on my st70 C3.  Sorry.  But I will provide a copy of the ARC manual once it arrives.  I will then be able to share a complete breakdown.

JP