[Ric Schultz]

I am putting the final touches on my new UCD based amps.  I would love to bring it over to others homes to see how it compares to the other latest and best Class D and other amps and to see if I need to do any last minute retweaking/revoicing.  Most important would be to compare with the Channel Island D200s and Nuforce model 9s (latest versions), as these are my most obvious competiton.  Any results of the listening tests would be kept confidential unless both parties agree otherwise (this gives me time to do any revoicing/retweaking and also gives others the time to sell their amps before rave reviews are posted (assuming my amps are better).  I already have one A/B/C scheduled that will have both the Nuforce 8s and the Roland 201s.  I work/live in Santa Cruz area but can come to anywhere in the bay area up to 1.5 hours.  Want to hear a super tweaked UCD 400 amp?  Let me know.  

Ric Schultz
Electronic Visionary Systems
http://www.tweakaudio.com
408-399-9708  please leave a message

[James Romeyn]

The only Class D fullrange amps I've heard in good systems are the latest Bel Canto eVo & the Spectron Musician III.  Pretty strongly disliked the III; (bass was high-powered but compressed dynamics).  Won't say what I thought of the eVo, but would love to hear what you think of it Ric, if you heard it.

[Ric Schultz]

Jim,
I assume you mean Spectron Musician III?  Have not heard the latest Bel Canto amp myself.  I did play with the Ice Power and Tripath modules so know some of their possiblilities.  The problem with most, if not all class D circuits is that they are not designed by really crazed tweako audio nuts.  They are designed by engineers, much like most digital gear so there is no reference on their part to how things can be done in the extreme.  So, the input stages on all the class D amps are not very good...ordinary op amps, surface mount caps and resistors costing a few pennies each, overly complex designs, etc.  The Hypex module is the first class D circuit that I have seen that is really, really simple and pure.  It can then be modded very easily, as well.  I believe, a super modified version done all out is going to show what potential there really is in a Class D circuit.  It is in the details where a product goes from merely good or very good to great.  John, at Spectron does not really believe in parts sound....not much anyway.  Every part, solder joint, damping, layout, grounding, effects the sound.  I will be even offering audiophile fuses treated with the gold goop. You can tell, I am very excited about this thing.  I have never heard such palpable super clear transparent sound from solid state before.

[James Romeyn]

yes, Spectron, sorry I screwed that up, will edit, thanks much rick, hope all is well w/ you & yours, good luck w/ the amp, sounds like it will be sweet.

[Charles Calkins]

Ric:
 I've got a pair of D-200's and I wouldn't mind putting them in a box and meeting you somewhere so you could do an evaluation. I live in (rainy)Martinez. N.E. of S.F.

                             Cheers
                             Charlie

[James Romeyn]

OK, here's what I thought of the latest BCanto: sterile to the point of exhaustion.  I heard a very well recorded orchestra & grand piano, my own CD.  Pure, crystal clarity off the scale, & to the same extent I could never get emotionally connected in any way shape or form.  Great dynamics, lowest audible distortion ever....etc etc, but I thought I coulnd never warm up to the sound.  I admit maybe I'm deaf & love distortion.  I don't know, & if someone told me they'd loved it, I would absolutely respect their opinion, unquestionably.  

No idea if there's a connection, but an analog engineer expressed an opinion to someone who probably holds more patents than anyone in audio.  The analog engineer expressed some opinion about switching amps failing at least one of the most elementary minimum characteristics for an audio amplifier (at least in the range above the bass).  Apparently in the bass range they pass this test, but above that, forget it, impossible, & the problem is inherent in the basic architecture & could never be fixed.  The patent holder, a very honest guy, did not express any difference in opinion, & in fact did agree w/ all or most of the analog engineer's conclusions.    

You obviously disagree or wouldn't be bothering w/ it.  I respect you a lot or would not bother posting.  The fact you are investing in the technology means there must be contradicting conclusions from at least two people I respect.    

I'm not decided, because I only heard two fullrange D amps on decent systems, the musician 3 at home, the bc on a nice pair of brand new Pioneer/TAD home speakers at CES (designed by the TAD guy who is among the most respected speaker designers extant).  The TAD models downstairs absolutely were among the best I've heard, powered by a row of several top dawg pass labs amps.

So, I'm curious, but not extremely hopeful.  Still, always an open mind.  If your production model appears somewhere near Petaluma or the East Bay hope you let us all know.

[Charles Calkins]

Jim:
 What amps are you using for comparison?

                    Cheers
                     Charlie

[James Romeyn]

When I had the muscian 3 here I had the ampzilla monos.  I thought the 3 was a toy with a lot of power.  Pretty clear, but no musical merit at all, loud but minimal dynamic contrast.  Since then I switched to a 25W EL34 (Audio Innovations Series 500, Neil Levinson's favorite amp, distributor later represented Audio Note, also distributed for a short while before they went out of business by NHT) powering the ribbon array only (ribbons not padded, 90.5 dB pure resistive load) & a 400W @ 4-Ohm Sunfire powering the midbass only (powered sub also).  Preamp is Dan Wright's ModWright SWL 9.0 SE.  CDP is TRL-modded Sony DVD/SACD 900.

I heard the belcanto at CES '06 powering the TAD home speaker line.  Don't know if Pioneer has sorted out the distribution for the TAD home line yet.  If you didn't hear them at CES maybe you never will.  As good as the speakers are/were there will obviosly be market resistance to an $8k speaker labeled "Pioneer".

[James Romeyn]

The engineer's opinion was that Class D has inherent HF oscillations folding down into the audio range.  He or she said one popular digital amp gave him or her a negative physical reaction in spite of having apparently good sound.  

I sure don't know about the above, & didn't have a desire to run away from the belcanto, I just didn't think I could ever warm up to it on a cozy night & want to listen to music through it.  No doubt at all the belcanto blew away the musican 3, so who knows, maybe Ric's will kick butt & take no prisoners....

[Ric Schultz]

The latest Bel Cantos use the Ice Power modules that have the built in switching supply (the ASP modules).  They are very good.  However, they do not make music.  They have a very cheap quad op amp on the input and 2 poles of junk filters before them, along with other problems.  At one time I replaced the first buffer with a zero feedback buffer (buf 634) and the sound was much more palpable.  I was going to sell these modules and bought 10 of them but after discovering the Nuforce amps I decided that the Nuforce with mods were definetly better than the Ice with mods.  Well, I had lots of problems with the Nuforce so decided to try UCD....well....they are in another league and super reliable as well.  

If anybody wants a stereo amp with the Ice Power ASP 500 modules (250 watt a channel into , with some mods, of course, I have one for sale.  I was just tonight taking my own prototype here and about to put it up for sale.  In junk chassis I will sell it for $500.  Basically the cost of the parts.  For this money, it is superb....but no UCD....or even a modified Nuforce.
 
Just tonight I put my modified to level 2 Nuforce 8 amps for sale on Audiogon for $700.....got to get some money.  Basically, this was a $650 mod (complete with two $120 Teflon caps)...so someone is going to get a $650 mod and only pay $50 for the amp....already have 5 emails all wanting it....I guess I should have put it higher, but cannot sell it for more as it does not compete with my lowest level $1150 UCD stereo amp.....too dang honest...oh well.

Ice was designed by nerds...he he.....so you are not going to get palpable sound.  If all you heard was Ice and Spectron, you are in for a treat.  The infamous guy at AVreality tweaked the non switching supply Ice modules in his super expensive versions...he changed the input filter, the op amps, added all kinds of film caps, etc.....now, with all those changes, I am sure it is decent....however, I don't think he sells them for less than about $10,000.  What he is mostly selling now are the same Ice power modules that everyone else is using...the ASP modules...and selling them unmodified, direct and cheap, because he wants to make a fast buck.  His ads are always up on Audiogon.

You cannot have amps designed by nerds that sound like music.....You need to treat the Class D amp as if it were a zero feedback single ended super silver tranformer, Teflon capped super tube amp....only then will you get what is possible with class D....to me the class D output stage has basically no sound of its own, besides the quality of the parts on the output filter...it seems to be very, very linear, like a fully class a circuit....but super cool.  By the way, there are very very few fully class A circuits...most are biased for 5-50 watts class A and the rest is A/B.  

Charles,
I will email you.  Yes, really want to do that A/B.
Ric

[Ric Schultz]

The latest Bel Cantos use the Ice Power modules that have the built in switching supply (the ASP modules).  They are very good.  However, they do not make music.  They have a very cheap quad op amp on the input and 2 poles of junk filters before them, along with other problems.  At one time I replaced the first buffer with a zero feedback buffer (buf 634) and the sound was much more palpable.  I was going to sell these modules and bought 10 of them but after discovering the Nuforce amps I decided that the Nuforce with mods were definetly better than the Ice with mods.  Well, I had lots of problems with the Nuforce so decided to try UCD....well....they are in another league and super reliable as well.  

If anybody wants a stereo amp with the Ice Power ASP 500 modules (250 watt a channel into , with some mods, of course, I have one for sale.  I was just tonight taking my own prototype here and about to put it up for sale.  In junk chassis I will sell it for $500.  Basically the cost of the parts.  For this money, it is superb....but no UCD....or even a modified Nuforce.
 
Just tonight I put my modified to level 2 Nuforce 8 amps for sale on Audiogon for $700.....got to get some money.  Basically, this was a $650 mod (complete with two $120 Teflon caps)...so someone is going to get a $650 mod and only pay $50 for the amp....already have 5 emails all wanting it....I guess I should have put it higher, but cannot sell it for more as it does not compete with my lowest level $1150 UCD stereo amp.....too dang honest...oh well.

Ice was designed by nerds...he he.....so you are not going to get palpable sound.  If all you heard was Ice and Spectron, you are in for a treat.  The infamous guy at AVreality tweaked the non switching supply Ice modules in his super expensive versions...he changed the input filter, the op amps, added all kinds of film caps, etc.....now, with all those changes, I am sure it is decent....however, I don't think he sells them for less than about $10,000.  What he is mostly selling now are the same Ice power modules that everyone else is using...the ASP modules...and selling them unmodified, direct and cheap, because he wants to make a fast buck.  His ads are always up on Audiogon.

You cannot have amps designed by nerds that sound like music.....You need to treat the Class D amp as if it were a zero feedback single ended super silver tranformer, Teflon capped super tube amp....only then will you get what is possible with class D....to me the class D output stage has basically no sound of its own, besides the quality of the parts on the output filter...it seems to be very, very linear, like a fully class a circuit....but super cool.  By the way, there are very very few fully class A circuits...most are biased for 5-50 watts class A and the rest is A/B.  

Charles,
I will email you.  Yes, really want to do that A/B.
Ric

[James Romeyn]

I know nothing to verify anything Ric posted above.  I do know he is a very honorable guy & have no reason to disbelieve it.  I've never read such clear & informative notes about the relative differences in Class D amps.  Thanks, Ric for writing in plain English that non-techno people can understand.  I would not miss a chance to hear your new class d amps.  They sound very promising.

Can you state the differences between yours & Dusty's CI amps?  Thanks very much.

[Ric Schultz]

Jim,
I cannot tell you exactly the difference between our amps because I have only seen a picture of some of the CIA inerds.  Once I have closely examined the CIA amps I will be able to tell you more but some things I consider proprietary and will not divulge for awhile... Basically it is all in the details.  I would say Dusty is about a 3 to 4 on the 10 point tweaker scale. 1 being someone who does not believe in parts (like John at Spectron) and 10 being someone like Serge Smidlin (sp?) of Audio-consulting.ch.  I would say I am an 9 on the tweaker scale...maybe 8.5....

Dusty uses good parts and execution but does not stray from the straight and narrow to much.  Dan Wright (Modwright) takes some of Dusty's products and does mods to them....so they can be improved.  I like to do things the sonically best I know of and am constantly reading the forums, etc. to find what others have found sonically enhancing.  

Here is one difference I can talk about.  Dusty uses a toroidal transformer that has both high and low voltage windings on the secondary side (the low voltage is for his regulated front end).  I use a separate transformer for the low voltage supply.  Less interaction that way.  Also he is using who knows what brand of toroidal tranny. I am using a Plitron.  Plitrons are one of the most expensive toroids you can buy but several people who have A/Bed transformers say they are the best sonically.  Also how you mount a transformer makes a noticable difference.  Dusty has a steel chassis and fastens the transformer down with the traditional steel plate and steel bolt....this is not good.  The Plitron trannies come with a potted center so I use Bronze bolt, washers and nuts and use Alluminum chassis.  More open sound this way.  You should all try this...if you have any equipment that uses a toroid....just remove the steel plate and steel bolt and leave the tranny in place....obviously don't tilt or it will fly around.....you will get more open sound....try it.  You can use tie wraps to tie it back down, if you like.

I use WBT nextgens as optional input jacks, Eichmann Cable pods as output jacks, use custom litz and cryoed hook-up wire, everything is hardwired (no push on connectors), damp the modules, use very expensive Jensen caps as options on power supplies, etc.  Don't think Dusty does any of the above.  Anyway, it is all a bunch of words at this point....the only thing that matters is how it sounds...if I am doing all these tweaky things it better sound better, right?  We shall see....er hear.

I hope my tweaker scale, etc. does not offend anyone (probably will, he he). I am sure Dusty is a great guy, etc.  However, the philosophy/point of view of the designer has all to do with the end results.

[James Romeyn]

Ric
I still think your idea from 20 years ago, to use binding posts only as a mechanical junction (not to conduct current), is brilliant.  I'm sure you have had many new & interesting ideas since then, especially w/ emerging technology like digital amps.

Related to your idea about loosening the transformer mounts: While listening to the brand new Genesis 60W KT88 integrated (very very fine!), on the latest Usher/D'Appolito BE10 Dancer, we simply removed the cage around the amp.  Subtle but significant improvement two people agreed.  

What do you think about the opinion that Class D has inherent HF oscillations folding down into the audio range?

Is the UCD technology synonomous w/ Hypex?  I've heard good things about Hypex.  

Thanks for your time.

[guest1632]

Ric
I still think your idea from 20 years ago, to use binding posts only as a mechanical junction (not to conduct current), is brilliant.  I'm sure you have had many new & interesting ideas since then, especially w/ emerging technology like digital amps.

Related to your idea about loosening the transformer mounts: While listening to the brand new Genesis 60W KT88 integrated (very very fine!), on the latest Usher/D'Appolito BE10 Dancer, we simply removed the cage around the amp.  Subtle but significant ...

Hi Jim,

Hypex is the same as the UCD design.

Ray

[guest1632]

The latest Bel Cantos use the Ice Power modules that have the built in switching supply (the ASP modules).  They are very good.  However, they do not make music.  They have a very cheap quad op amp on the input and 2 poles of junk filters before them, along with other problems.  At one time I replaced the first buffer with a zero feedback buffer (buf 634) and the sound was much more palpable.  I was going to sell these modules and bought 10 of them but after discovering the Nuforce amps I decided that the N ...

Hi Rick,

Wel, I will indeed be interested in your A/B of your amps with Dusty's. I have understood that there is some proprietary circuit designs in that amp he builds. Another one to watch for is the one from Stan Warren.

Ray

[Ric Schultz]

No one knows except Dusty what he has done to the modules.  He is being secretive....so we don't know if he changed one part or what.  You change one part and you can call it proprietary.  I will look VERY closely at his module and I will let everyone know exactly what he has done (unless he has done something I can steal and use that I don't want any other competitors to know)..he.he....now my own proprietary mods....he he...I am NOT going to reveal all either....he he....you will have to wait till one of my competitors gets ahold of my amp and reveals all....the drama unfolds...he he...

There are always engineers who are talking about folding down....I was one of the first to use no analog filtering on the output of DACs....engineers had a field day with that....now there are tons of DACs with no analog filtering and a bunch that have no digital filtering as well...most feel they sound terrific.  Can you hear the folding down from an amp on your speakers?  If an amp puts out one volt peak to peak 400K sine wave that rides along the signal...do you think you could hear that?  I doubt it.  How far would it have to fold down and how much would remain at what frequency....say .1mv at 1K?  could you hear that?.....if you put your ear up to a speaker with the UCD module on you will hear nothing...nada...zip...and yet the 1volt peak to peak voltage is there.  Obviously, if you put more filters on the output of the amp there would be less carrier...however you would veil the sound with the parts.......this is what Nuforce had to do because their amp puts out so much RF....they added another coil and cap on the output to remove some of the RF garbage that is part of the design.....their filter does not filter the carrier (400-500K) however....some other companies that make Class D stages do use a 4 pole filter instead of a 2 pole....does this help?  I bet is just makes more parts sound (veiling).  The same engineers freak out when they see the output of a SACD player....talk about noise!...in fact, some engineers refused to believe that SACD was any good at all because of this.  Now people who listen, have different opinions.  Do you want good measurements or good sound?  Nice to have both....but they don't always go together.

[James Romeyn]

Ric
Very interesting, & provocative too!

It's also interesting that you brought up SACD.  I noticed I get fatigued quite rapidly of SACD.  But at least one component designer mentioned to me, unsolicited, that SACD has a high fatigue factor.

[TheChairGuy]

Ric,

I'd love to come down and A vs. B my Odyssey Khartago Mono's (it, too, being natural competitors pricewise for you) versus your Hypex creations....but finding a whole day to devote to doing so is near impossible these days.

It's my busy season now.  I'm up in (now soggy) Marin.

Good luck to you - thanks for the great postings  

[James Romeyn]

Hey John
It's wet, but up here in Sonoma I haven't seen greens this bright since I left Kawai...commuting is the bad part.  People just freak out & don't know up from down when it's pouring so hard....of course not being able to see doesn't help.