Where is the best place to put tubes in the system?

JLM · « **on:** 23 Dec 2010, 09:01 pm »

I have very little experience with tubes (and that was "iffy") but would like to try.

But I don't want layering of tubes in my system, besides I'm cheap. And I don't care for the idea of three different tubes, seven tubes total for a single piece. (I just want to stick my little toe in the water to start with.)

So should my only tube(s) go at the source (I only do digital so it would be a DAC), preamp, or power amp?

TIA tube crew

werd · « **Reply #1 on:** 23 Dec 2010, 09:09 pm »

Try with a preamp since you can tube roll without any experience adjusting bias. Signal tubes are just plug and play on a pre.

Wayner · « **Reply #2 on:** 23 Dec 2010, 09:25 pm »

I agree with werd. A tube preamp with give you a taste of that tube sound and those small signal tubes last for years and years. There are 2 types of this application, pure tube and hybrid. The Hybrid is a little bit of a different animal, but there are also hybrid amps and DACs available.

The preamp would be the cheapest way to get your feet wet.

Wayner

jtwrace · « **Reply #3 on:** 23 Dec 2010, 09:27 pm »

No doubt that a tube front end piece is a great way. I have the Dodd Buffer and it's awesome! It replaced a very expensive all tube pre.

JoshK · « **Reply #4 on:** 23 Dec 2010, 09:30 pm »

My experience with a limited number of tube dacs, together with general intuition about such designs leads me to think that you aren't going to get a lot of benefit of tubes from a tubedac, some but not a great deal. This is because the analog stage of a dac needs to do a lot of amplification while still maintaining a decent output impedance which mandates a topology that is more SS like (or sounding) despite being made of tubes. This is arguable of course, but I've found this to pretty much hold true.

A tube preamp is likely the easiest place to insert tubes into a system while gaining some qualities inherent to tubes. However, typically this boosts gain far too much unless the amp is of a low gain type. This brings its own issues to the table. So it isn't an easy answer.

The benefit of tubes, in my humble opinion is obtaining gain without the inherent consequences of higher order distortion products and time smearing feedback. Adding gain to a system that doesn't need any isn't advantages. The point isn't to add euphonic coloration, which, tubes done well, isn't what it is about.

Note: let me just add, that I do think tube dacs can be beneficial to a system, but that their interjection into the system isn't a wholesale endorsement of the technology, its much more subtle that elsewhere IMO.

bunnyma357 · « **Reply #5 on:** 23 Dec 2010, 10:06 pm »

Depending on what you have, a tube buffer can be an easy way to get a "taste" of tubes. You can put it betwen source and pre, between pre and amp or in a tape loop so you can switch it in and out of the signal chain. I used a Musical Fidelity Tube Buffer with my old Yamaha receiver, and liked what it did for the sound.

Eventually, I ended up going with just some simple & cheap chinese integrated tube amps, but I probably wouldn't have tried tubes at all without a stepping stone like a tube buffer.

A few examples of tube buffers (No affiliation or experience with any of these sellers):

http://www.pacificvalve.us/YAQINGallery.html

http://cgi.ebay.com/LNIB-Musical-Fidelity-X-10-V3-Tube-Buffer-/150538335344?pt=LH_DefaultDomain_2&hash=item230cc8b470#ht_1871wt_907

http://grantfidelity.com/site/catalog/52/tube_processors

http://www.decware.com/newsite/zbox.htm

Jim C

twitch54 · « **Reply #6 on:** 23 Dec 2010, 10:17 pm »

Quote from: JLM on 23 Dec 2010, 09:01 pm

I'm cheap.

stick with a boom box and plug a nite light in next to it.

..................on the serious side I concur with wayner and werd..

dangerbird · « **Reply #7 on:** 23 Dec 2010, 10:35 pm »

Pre--a good tubed pre/ss amp combo is hard to beat.

TheChairGuy · « **Reply #8 on:** 23 Dec 2010, 11:00 pm »

I've tried multiple combo's of the most suggested 'tube preamp/SS amp' and they've paled next to 'SS preamp/tube amp(s)'.

The necessity of benign loads suitable for the tube amp (and often low capacitance cabling) is most often a must...but once that's dialed in, the tube elan at the end of the chain is often the best.

I haven't yet found a tube pre-amp that amplifies delicate phono signals quiet and robustly enough....and I prefer full featured SS preamps (with phono) to cut the rca joints, solder points and interconnects involved (never good for eeny weeny phono voltages)

Unless JLM is making another serious about face in his beliefs that he has made plain in the past - I don't think consideration of vinyl playback is a parameter here.

I've heard some digital front ends with tube outputs...those are starting to attract my attention as they improve the sonics impressively, too.

So, tube output front end + solid state preamp + tube amps + minimized and low capacitance cabling + benign speaker load = SONIC BLISS.

Full featured preamp and fully dual mono amplification (including power supplies) prescribed for the above, preferentially

John

davidrs · « **Reply #9 on:** 23 Dec 2010, 11:28 pm »

Quote from: TheChairGuy on 23 Dec 2010, 11:00 pm

I've tried multiple combo's of the most suggested 'tube preamp/SS amp' and they've paled next to 'SS preamp/tube amp(s)...the tube elan at the end of the chain is often the best.

I've heard some digital front ends with tube outputs...those are starting to attract my attention as they improve the sonics impressively, too.

So, tube output front end + solid state preamp + tube amps + minimized and low capacitance cabling + benign speaker load = SONIC BLISS.

John

Follow that Guy in the Chair! ...or is it a throne?

I am going to ask you to define what you mean by "Best"?

Pending your definition, I am with John - focus on a tubed amp.

Elizabeth · « **Reply #10 on:** 24 Dec 2010, 12:13 am »

A tube amp IS probably the BEST way to love tubes...
BUT!
the OP wants to get into tubes easy.. I have owned several tube preamps, and have to say as a tube-o-phobe I can handle tubes in a preamp. (as long as not too many.. as the OP asks!)
I had (for a short time) an Audio Research SP-10 Which has nearly a dozen tubes.. I sold it because that was just WAY too many tubes for a tube-o-phobe. (and since the tube in it were pretty crummy.. tube rolling/replacement was in order.. this tube-o-phobe got scared.) I bought an Audio Research Sp-15 which has 3 tubes in the phono section. Good tubyness.
Than I bought a VAC Standard to use as a tube buffer.. The VAC has four tubes, they will last a very long time.. Another tube goody for this tub-o-phobe.
I have several tube headphone amps too. They also use just a few tubes, and do not need biasing. Also good for me. One tube headphone device, the SinglePower I have has sets of several tube exchange plugs that came with it, and all sorts of alternate tubes.. A good way for me to learn more about tube rolling.. the person selling it said the tube alternatives was making it too confusing for him!)
The biggest problems for a tube newbie are: tube rolling confusion, tube Purchasing confusion, and power tube biasing. (and the fear of tube/resistor -going-up-in-in-smoke-in-power-amp.. fears.)
So, as a "tube-o-phobe" who likes tubes, I say to the OP go for the preamp with a few tubes. Something that has a hybred design, or a solid state power supply, and perhaps a set of four signal tubes.
Brands that come immediately to mind are Audio Research, Conrad Johnson.
ARC is less tubey sounding. Where Conrad-Johnson is a great tube like sound.
So...
This is my opinion and I stick to it.
HOWEVER, if you have a good LOCAL tube expert dude you trust, then by all means go ahead and try whatever comes your way. If you do not have a tube guru nearby... stick with the easy stuff first. IE : tube preamp, with good customer service from the factory. IE Audio Research (even really old models are serviced) and Conrad Johnson

TheChairGuy · « **Reply #11 on:** 24 Dec 2010, 12:35 am »

Good points, Elizabeth....about keeping it simple and tube preamp is simpler from that basis.

Regarding simplicity - here's one possibility that I've long considered to keep transmission lines short and succinct.....an integrated with a SS preamp and tube outputs. Rare, but at least one company made it in the past decade - AMC.

http://cgi.audiogon.com/cgi-bin/auc.pl?intatube&1293245185

Hey, it's even got a phono stage thrown in....

With a day left, this unit might go for less than $200.00 to try and it has the very unusual combo of SS pre-amp stage and tube outputs (classic EL34's...two per channel).

It's even cryo-treated (coming from MN)

John

JLM · « **Reply #12 on:** 24 Dec 2010, 12:59 am »

Thanks for the input.

It seems like there is consensus here for a tubed pre-amp. I agree with you Josh, most (not all) reviews of tubed DAC’s aren’t overwhelmingly impressed with the tube solution. And over the years I’ve seen a mixed bag of user reviews of various tube buffers.

Even the entry level cj is too expensive for me. How about a Mapletree 2A? Another option might be a hybrid tube pre/solid state power integrated amp. The fully balanced 150 wpc Shengya A-216 uses mini tubes in the pre (rated life = 200,000 hours!) and sells at Grant Fidelity for $1,150.

(John I don't want to go backwards in power or quality.)

Wind Chaser · « **Reply #13 on:** 24 Dec 2010, 01:05 am »

I had a Decware ZBOX built into a cheap Pioneer DVD player. It transformed that cheap DVD player into something special. Sold it to Rocket_Ronny who thought it was at least every bit as good as his expensive Metric Halo.

Having owned tubes just about everywhere, I'm not inclined to agree with the preamp over power amp advocates. Instead I think you should consider an integrated amp. But there is a caveat. Don't assume that just because something has tubes that it will be better than its non tube counterpart. I've heard more tube crap than SS crap.

davidrs · « **Reply #14 on:** 24 Dec 2010, 01:22 am »

JLM,

How much power are you looking for and what are your speaker specs?

I, also, had a great deal of nervousness and trepidation before taking the plunge into the tubed world, but am so happy I did. And it really wasn't a big deal, at all.

If you are looking at a pure tubed amp or even an integrated, I really don't think you will be overwhelmed with the move into it.

Using the market, solely as a proxy, in terms of different units offered, tubed separates far far outnumber tubed integrateds which far outnumber hybrid solutions. Which, is a pretty decent indicator of where the hobbyists fall. Always good to see how folks are voting.

Not saying going with a tubed pre is a bad choice, just that you will likely achieve your goals more completely with a tubed amp, baby steps non-withstanding. And amazing support from the AC community in this area.

Great that you are doing this. And have fun with the journey, which ever approach you start with.

TheChairGuy · « **Reply #15 on:** 24 Dec 2010, 01:40 am »

Quote from: JLM on 24 Dec 2010, 12:59 am

(John I don't want to go backwards in power or quality.)

The quality seems to be there on the AMC unit (look up CVT3030 reviews and you'll find a few if helpful), but I don't know what type of power you're needing.

Generally, small living spaces and easy loads for speakers mean you don't need too many tube watts....generally anything over 25watts of push pull is sufficient

Anyhow, I echo DavidRS on this - just have fun with the journey no matter the final component choice(s)

JLM · « **Reply #16 on:** 24 Dec 2010, 02:09 am »

I currently use Channel Island Audio VMB-1 40 watt monoblocks and want to make a significant power (at least twice the wattage) and quality step up for under $2,000 USD integrated (pro-rate for separates). My speakers are 91 dB/w/m, 8 ohm, 30 - 20,000 Hz. I listen to mostly jazz/classical at moderate levels nearfield in a 2,000 cu. ft. room. Other users of my speakers (Brines Acoustics FTA-2000) rant that they benefit greatly from extra power (like 200 watts).

I'm looking for image density/specificity/expansion and non-euphoric lushness (does that make sense?) from tubes. But I still want tight/deep bass, honest (not warm) midrange, no noise, highly resolved detail, and improved micro/macro dynamics.

Heat is not a concern as my listening room is in a northern basement, but I'm not buying anything that uses tons of different/expensive tubes.

wilsynet · « **Reply #17 on:** 24 Dec 2010, 03:55 am »

Music Reference RM-200 available on Audiogon right now.

chadh · « **Reply #18 on:** 24 Dec 2010, 06:01 am »

I used to have the VMB1s, and chose to try a tubed pre-amp. It was a wonderful way to go, as far as I was concerned. And the benefits I reaped were precisely in "image density" -music seemed to have more body. Even if you're looking to step up in power, I'd certainly recommend trying the tubed pre with your current amps.

If you're interested, I still have mine lying around (a downright cheap Space Tech Labs QA-001). It takes just a pair of 6sl7s or 6sn7s. It has lower gain with the 6sn7s - and I never felt I needed gain while using the VMB1s. You're welcome to borrow it for a bit, to see what you think. It's not going to be the last word in pre-amplification. But it might be fun to hear.

Let me know.

Chad

JoshK · « **Reply #19 on:** 24 Dec 2010, 06:04 pm »

The Mapletree is stupid good for the money. It bettered many $2k preamps I tried. Its very linear, so you get the sweetness of tubes without the drawbacks. It should mate well with your CI monoblocks. You might get a bit too much gain, but you'll just have to see. Tubes done well, which I include the Mapletree here, should give you what your after. You might not need more power.

P.S. I do think tube amps are more of an ultimate solution but really good tube amps are expensive typically and hard to come by. The tube preamp should get you there for much less money. There is more than one way to skin a cat.