Review: Tube Audio Design TAD-60 Tube amp


Category: Amplifiers

I'll start by saying that I've been into higher-end audio for a few decades now, and quite a lot of equipment has been through my hands to this point (half the fun of this hobby). Somewhere around 12 years ago, I'd come to realize that I preferred tube amplification over solid state in terms of an overall involving presentation of the music, and ever since then have owned tube stuff (brief flirtations with various solid state devices only helped to enforce this notion).

Which brings me to the discovery of Tube Audio Design, the provider of components conceived by Paul Grzybek (of Bizzy Bee Audio fame), built to his specifications by a very reputable Chinese manufacturer, and then hand-finished by Paul in his shop located in Wheaton, IL. (His offerings are available exclusively online; detailed product info is found at http://www.angelfire.com/biz/bizzyb/index.html)

The TAD-60 amplifier is built like the proverbial tank; overall appearance and heft (not to mention its specifications) in my experience indeed belie the modest asking price. With its stainless steel chassis and almost 1/2"-thick black anodized face, the relatively compact package portrays a masculine but elegant stance (also included is a lift-off stainless steel tube cage). All function controls are easily accessible from the chassis top, as are the tube bias test-points and adjustment pots (a digital voltmeter is included too).

EL34-based, the TAD-60 is rated at 60wpc in UL-mode, and 30wpc in switchable-on-the-fly triode-mode. Other standard features include adjustable input sensitivity and adjustable global feedback, adding flexibility to a host of possible preamp and speaker combinations (the input sensitivity control may also be used as a volume pot in a single-source direct input configuration).

Listening to the TAD-60 after the recommended 30 hour break-in period and beyond, the music really began to open up, and along with the TAD-150 preamp, I was experiencing just about every CD I spun in a whole new manner - I'm particular to small-ensemble jazz and female vocals - there was an in-the-room conveyence of the music that I found startling at times - present is deep, tight bass, a glorious midrange, detail, depth, and an overall natural presentation that allows hour after hour of enjoyable listening. I've found that the feedback adjustment permits a fine-tuning of balance between dynamics and warmth, and was able to "lock in" the amp to my speakers for what sounds to be a perfect sonic match (just a tad of feedback along with the triode-mode setting seems to be the magic spot in my case).

Without attempting to describe every sonic attribute I'm hearing (though I'm happy to answer any particular inquiries), suffice it to say that the TAD-60/TAD-150 combination strikes a synergy and glow that is especially musical, and is among the finest I've had the pleasure of owning. The TAD-150 has already been highly praised in at least a few user and online reviews, and I bet the TAD-60 will soon be recognized as a similar standout. If you happen to be in the market for high quality, reasonably priced, excellent-sounding gear, just take a listen for yourself, and you will hear what these components can do for music. (Paul also offers a 15-day in-home trail period.)

Note: I have no financial interest or business relationship with Paul Grzybek or Tube Audio Design.

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Magnepan 1.6QR, California Audio Labs CL-10, Music Hall MMF-5/Goldring G1012

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ggeers222
I asked Paul the same question earlier today. Here's what he writes: "It appears the bias pots on the 60 do not swing low enough to do the class A mode with larger tubes.
Definitely try with 34's. So far all are really liking the A sound. Could try quasi-A mode - setting the bias low as possible on one 88, maintaining ~700 on the other. This will offer similar results, just not as ideal. Another twist - try running an 88 at 700 and a 34 at 175. Who knows this might even be better." Paul mentions a 700 reading in his reply because 2 of my KT88 are reading at 710. So it appears that you can't do it with KT88s unless you're willing to mix them in with a pair of EL34s. I'm going to try it tonight. I'll let you know how it goes. Btw, has anyone tried the Class A bias with all EL34s?
I tried the Class A Bias with good results. Most noticeably the mids sounded great. I may even try & mix the 34's with the KT88's.

Jeff
Ok. So I rolled in the stock EL34s at V1 & V3 matched with my EH KT88s as suggested by Paul, and I've listened to about 20 songs (some on cd some on vinyl) that i know very well, and the first thing i noticed was that the highs were a bit rolled off; you could say a little warm or softer. Which isn't necessarily a bad thing because the EH KTs can sound bright. The bass has nice punch, and the mids are lush and defined (just like having all 88s in), but the added warmth of the highs makes for a different and pleasant setup. Its not better, just different. Also this setup makes for a friendlier volume control. I have the TAD150 pre, and set between 9-10:00 it has good definition now. With all 88s, I was at high volumes with the dial at 10-11:00. Not cool when the wife and kids are sleeping. Yeah, i sneak in late night listening. I'm going to try the Class A setup with all EL34s next, and then i think I'm going to get those Penta KT88s. After that I'm going to chill for a while cause all this new vinyl is killing my budget - got a an MMF-7 (first table ever) and I'm loving it.
Onotu2,

I was hoping this was possible. I could probably stand a bit of roll off in the highs. So, which tube and its corresponding bias level in which 'V' position? thanks.

Dave
Dave,

Place the EL34s in the V1 & V3 sockets (bias low, eg 175), the KT88s or other large tube in the V2 & V4 sockets (bias high >=500). Mine are set at about 705. I'll do some more critical listening over the weekend, but so far I like what i hear. I will probably live with it for a few days before trying all EL34s in the Class A setup.

Lou
I've tried the class A setup with a mix of 34s and 88s, but wanted to hear how they would sound with all 34s, so last night i made the switch. Gotta admit, i couldn't really tell the difference. The bottom was maybe a little softer (very subjective here), but better than the non-class a setup for sure. The mids and highs were very similar to the mixed tube setup, that is too say lush, airy and right on. At low volumes it was almost hypnotic; the definition and mids were that good. Most of my listening was on vinyl; genre was classic rock, blues & jazz. Overall, I think I like the all 88 setup best (albeit without the class A bias), but that could be because it was such a jump from the stock 34s at the time. I guess what impressed me most about the all 88 setup (too much tube rolling can be a bad thing) were the dynamics and balance of highs and lows. However, I do like the class A setup, and will stick with all EL34s (mids are the best) for now until I can afford (and my wife lets me) purchase 88 Pentas, or dare I dream, a quad of Telefunken or Genelax Gold Lions. Yeah, I got the bug.

PRE-AMP: TAD-150 Signature
SPEAKERS: Onix Ref 3
SUB: Rocket UFW-12
TABLE: MMF-7
I'm in the middle of purchasing with Paul and I'm curious to hear any feedback on the auricap upgrades.

Is there anyone out there that had their unit upgraded and felt that the unit outshines the stock one? If so, please indicate the areas in which you found the greatest gains and if possible, any other sonic differences between the two.

This info is highly appreciated as I'm impatiently awaiting the arrival of my new addition!

Thanks in advance for any info at all!

BTW, I will be running with a Quicksilver Audio Remote line pre-amp.

Regards!
I think this amp is tremendous. The clarity (realism) was the big surprise for me. I am enjoying going through my record collection. It like everything is new again.
With all that I am reading about the JJ KT77 I guess I just have to try them. I do want to try some NOS 12ax7 and 12au7's
The amp has about 60 hrs on it and seems to be settling in so I can start evaluating. Paul has been very good with suggestions.
He was curiously quite about a request for a schematic.
I am finding the amp a little forward and the image is larger than my previous set up. My speakers are Vandy 2Ce's. The TAD-60 is in triode mode with little or no feedback. I have not tried the Class A bias yet.
I do have plans to glam up the TAD-60 a bit. I like adding exotic wood sides. I hate the silver cap on the power tranny as well as the tube shields on the 9 pins. I cannot hear any difference whether the shields are on or off. The feet have to go. I feel the plastic/hard rubber decouple the amp and trap mechanical vibrations in the amp. My music room is in the basement so I have thin carpet over concrete. I do my best to couple all my equipment to the concrete. For the TAD-60 I built a 4 inch thick wood block out of beech butcher block which have spikes to couple it to the concrete through the carpet. Right now the TAD-60 is on teak blocks that do not touch the plastic feet. This does a nice job coupling the amp to the 4 inch butcherblock base. I think the only thing better would be the Mapleshade brass footers.
I recently purchased a pair of Klipsch Fortes because of all the good buzz I've heard on the Net about them. When I first mated them to the TAD-60, I wasn't that impressed, but I was using the amp in ultralinear mode. So, I switche to triode mode. Boy, I was certainly impressed by the sound. With my old ScanSpeak speakers, triode mode always sounds too soft. With the Fortes, I heard the best balanced sound that I've every heard and vocals still retained the palpability that tubes provide, but now all the music, including orchestral has that 'just right' musicality.

The story doesn't end here. When I measured the bias, it was over 100 mV low on all tubes, so I readjusted and the sweetness of the sound became hard to believe.

Klipsch Fortes - try 'em with the TADs!
I've been rolling the pre tubes and was wondering if anyone has tried an NOS BugleBoy long plate cause it's the one ax7s I haven't tried. Btw, if you haven't tried swapping the pre amp tubes, you're missing out. The change is HUGE. In fact, had I known I would have started there first instead of the power tubes. Lately, I'm running the 34s in Class A mode, but i have a quad of Penta solidplate 88s in waiting. Anyway, I tried quite a few NOS tubes in the center position, but found the ax7 variety to be best (just punchier and bigger soundstage) and settled on the Mullard sound; great mids, lush but not too much (imo), well extended, nice bass, and of course, warm, but not too tubey. The Mullard is a 10M, but I have a longplate coming tomorrow - I'll let you all know how it goes. Been wanting to try a Bugleboy long plate, but the eBay prices get crazy and rolling tubes in of itself can get crazy too, so I'm trying to ease up. In general, the TAD-60 out of the box is awesome (drives my Onix Ref 3s just right), but its nice to know that it can be tweaked, and the changes are more than subtle. Has anyone else tried rolling the preamp tubes? If so, please share :) Btw, if you'd like to try a nice NOS tube that won't break the bank, the RCA blackplate with the square getter ('50 - early 60s) was really nice. Great mids, mid/highs were very detailed, and bass was punchy but controlled. Overall, a great tube, but with my speakers it was little edgy. Oh yeah, as for the au7s, i settled on Telefunken au7s. For the most part i didn't notice much change in rolling here and I tried some RCA cleartops w/ gray plates, too. But i left the Teles in, just cause they're Teles.
I am a little embarassed. I fixed my image problem. I had my right woofer phased reversed. When I straightened that out the image was right on.
Armed with confidence I tried the class A bias and now I am in love with this amp. Paul's last e-mail suggested pushing the bias on V2/V4 to 600 which I will try in stages. I am at 500ma now and will start moving up. I am going to order some Pearl coolers. for the EL34's.
I have some NOS 12ax7 and 12au7 on the way.
The standard power supply in the latest batch of 60's is smaller, producing 40 watts no matter what output tube type is used. This allows a lower initial price to help those on a tight budget. Power supply is the engine, tubes are the tires. Paul
What is everyone using for the one 12AX7 and two AU7 tubes? Is anyone using alll 12AX7 or do you need to replace with the same type of tubes. I just put two GT AX7 in the preamp and while I am still evaluating I think the total system performance or net change may not be evident until I replace the AU and AXs in the TAD-60...
Eagleman, in the the u7 slots, Paul suggests keeping u7s. I'm using RCA cleartops, but have some Telefunken's i like to use as well. The greatest difference in sound comes from the swapping the x7 position. I'm currently using a GT "Mullard" reissue, but i've also tried a Mullard 10M (nice tube, but too bloomy & boomy for me), an RCA 5751 blackplate (really like this one and 5751 in general, yeah I read Joe's Tube Lore), and a Mullard x7 long plate, which has great warm mids, and nice bass. I've also tried a Tele u7 and Tele t7 in the center position, and find the t7 pushes the mids too forward for my taste. The u7 has nice seperation and clarity but lacks the presence of a t7 or x7. I also found the highs were rolled off a bit. One nice thing about the "relaxed" sound stage of the u7 was that you could turn up the volume and things didn't get messy; seperation and clarity remained. Have fun.

Lou
I use a Mullard 12AX7 in the A7 socket and a pair of GE 12AU7 in the U7 sockets. My TAD-60 came with some unknown U.S.A. made 5814A's and a Sovtek 12AX7WXT+. Changing out the Sovtek to a Mullard is a big improvement as one would expect. Also the very slight thump on power off is completely gone. This set up along with the VA KT88s results in a very tight bass, a beatiful midrange and slightly rolled of highs.

Just wanted to share a tweak that has made a HUGE difference; Herbie's Hal-o Dampers http://herbiesaudiolab.home.att.net.
Wasn't expecting much, but I couldn't believe how much microphonic smear and noise my tubes were emitting until I slipped these on the power and pre tubes. The sound stage went silent and clarity/separation were night & day. And talk about controlled tight bass. My jaw was on the floor. It's like having new gear. Seriously. Can't say enough good things about them. Best of all, they're affordable, and you get a 90 day trial. Some folks on the web have commented that dampers also dampen music, but I did not find that to be the case. Things are more musical and enjoyable than ever. Play some busy passages loud and be prepared to smile.
Hi Lou,

Where did you get those U7 RCA Cleartops? From reading about them it appears to be a good fit for my speakers. Vandy 2ce sigs. I have the Groove tube in the X7 spot and it seems to be a nice improvement over the Sovtec. More punch and air...
My TAD-60 is on the way. I am moving my wonderfully satisfying Cayin TA-30 to the second system. Has anyone run the 60 without a preamp?

Thanks,

Bud
I have owned the TAD-60 for six months and I am ready to tube roll. I adjusted the bias to single ended and noticed that the music is more smooth but not as dynamic.

I have read many tube posts and it seems that the most sought after 12ax7 is the Mullard 10M. Has anyone tried this tube in your TAD-60? I want to get some feedback before I spend $150 for the tube.

Thanks in advance.
Bud,

I run my TAD 60 as an integrated. I only have one source so this makes things simple. Currently I am using a Mullard copy 12AX7 from Groove Tube in the middle position. This is a great new production tube. The 12AX7 that Paul shipped with my amp was a JJ. The JJ is good, but I prefere the tone of the Mullard copy. The 12AU7 tubes that came with the amp were EH, but am now using NOS Mullards. Got all these tubes from Upscale Audio.

Michael
Scooby, the 10M was the first tube I rolled into the x7 slot (paid $150 on ebay, seems to be the going price) and overall I found it too be very warm and smooth, especially the mids. The low end was deep but not boomy, but the highs (while not bad) were not as sweet as you'd find in a Tele x7 or Raytheon 5751. Overall, a great tube if you're system is in need of a "warming" influence. If that's the sound you seek, you may want to save some cash and go for a regular Mullard short plate (which is what the 10M is only "hand selected for balance, yada, yada) and move on from there before laying out some serious cash. The GrooveTube x7 (a current production) that is supposedly modeled after the Mullard shortplate is a really nice tube (cheap too) but its much more dynamic and lively (not as warm and creamy) as the 10M. If you can get deal on one, I'd also try a Mullard longplate.

Lou
Another X7 replacement to try rolling:
I have Chinese Triple Mica Mullard T7 knock-offs that are amazing! Yes, a T7 in the X7 socket. Only $10 + ship.
This is the same tube I supplied in the TAD-150 preamp that many seasoned tube rollers stated they could not top. Sounds better than the real Mullard triple mica T7! Paul, Tube Audio Design, Available on the Sale price page.
I decided not go for the 10M because of the cost and I wanted a more lively and dynamic sound. I read many reviews of the Mazda 12ax7 silver so that is what I purchased. The stock tube China 12AT7 had a wider soundstage, more gain and overall more pleasing sound than the Mazda tube. I noticed that the Mazda tube is generating a moderate hum audible from 20 inches away from my TAD-803 even with the preamp turned off. Did I get a bad tube?
The TAD-150/TAD-60 combo has been viewed quite enthusiastically in this thread. I have read elsewhere of a Cayin TA-30 integrated getting paired with the TAD-150 and receiving glowing reviews so the TAD-150 had fans in a number of camps.

I know there are other pre-amps out there I’ve seen suggestions of using:

-- Monarchy Audio M24 tube DAC/linestage
-- Quicksilver Remote linestage
-- Eastern Electric Minimax
-- Octal-based Mapletree Linestage 2A SE

Now that the TAD-150 plant has closed, has anyone heard from Paul G. whether he is going to find a substitute? Just curious now that the TAD-150 is no longer available, in addition to the above suggestions, what are people are thinking of matching to the TAD-60.
The Tele smooth plate was the better of the two for me (more extension and vibrant) but in general I wasn't impressed with either. I think unless you spend big bucks to go for the ECC variants of Teles, you're money is best spent elsewhere. I thought the Mullards (longplate), Raytheon 5751, RCA 5751, & Sylvania 5751 (all 3mica bp) were superior and offered a huge improvement when compared to the Teles. I also liked the Groovetube which is supposedly based on the Mullard shortplate. I have ECC801s (the t7) in the TAD150 and they are absolutely stellar so I'm not a Tele hater. And if the ECC803s (the x7) weren't super expensive I'd have demoed them, too. The x7 I finally settled on for TAD60 (no joke my shopping is done) is the Sylvania. This tube is everything folks say it is. A close second is the Raytheon. The Sylvania edges it out with its awesome mid-range.
Should be getting my EH 6CA7s today on Paul's recommendation. Can't wait to try them. How long have you been running yours?

Dave
OK, I have approx. 12 hrs. on them now and I tend to agree on your observations regarding cleaner vocals, better, extended highs, soundstage depth but also tighter bass. Not only do the vocals sound cleaner, but the entire midrange for that matter. I've been listening to familiar and well recorded LPs and have noticed subtle neuances in many of them that I hadn't observed before. What a joy it is to have inexpensive, new production tubes that behave so admirably. BTW, anyone considering the EH6CA7s should get them through Paul @ Bizzy Bee as he truly load matches each quintet (one as a spare) for hassle-free installation/biasing (Thank you, Paul!). When you set Paul's tubes, they stay put!

Dave
what speakers are you using with the 150 and 60 combo? i have totem arros with the 150 and a ss amp with 200wpc. considering moving to tube amp, totem recommends antique s l and prima luna.
I have a pair of spendor s5e's with 150/60 combo and it really sings....very synergistic match
The 6CA7s from Paul are da BOMB! Get them. I have them setup in Class A mode and totally agree with previous comments. Tight, deep bass, extended highs (not harsh), and huge soundstage. Big improvement. You won't miss the KT88 or the lushy mids of the EL34s. They do need sometime to break in but you'll notice it (kinda jumps out at you) after @ 20hrs, but really start to settle in after 50. And get them from Paul because he really does matching, and having an extra tube always helps.

Lou
Lou..I agree with you about the 6ca7's. I found the same thing you did..that the el 34's just didn't have tightness that the 6ca7 do in the bass especially in the set mode. I don't know if any further rolling would improve on these. What do you think?
Lou:
I have appox. 12 hrs. on my 6CA7s. Everything said here is right on the money. I also noticed they have more power in the bass. I can actually feel more air being moved by my speaker as compaired to the EL34s. They are more dynamic than EL34s. The 6CA7s sound so good now, I cannot wait until they are fully burnt in.
Lou what input and P/S tubes are you using in the TAD60? Have you found changing the P/S tube makes much of a difference?
Thanks.
Michael
Michael..I have replaced the 12ax7 with a nos sylvania and it seems to deepen the soundstage quite a bit...I have replaced the 12au7 with nos rcas and I can't that made a great difference
Thanks Larry. I too have done some tube rolling of the 12AX7 and that seems to make a significant difference. I kind of thought the P/S tube probably didn't make much of a difference. I recently bought a few different pairs of 12AU7s I will try, just to hear what happens.

Michael
Swapping out the x7 makes the most dramatic change. I like the Sylvania 3mica blackplates which is 5751 with a bit less gain, but oh so nice; especially mids, but bass and highs are great too. The u7s make less of a sonic head turning difference, but a difference none the less. Better NOS tubes will clean things up and provide greater transparency. I like the RCA cleartops. If you can find them under the Conn label (made for Baldwin organs and well made) get them cause they're typically cheaper. I also recently tried a JJ/Tesla E80CC which has a slightly bigger load than u7s (Paul ok'd them) so overall they are a bit more forward, and a nice cheap alternative if you can't find the cleartops. Btw, i also tried Telefunkens & Mullards (not cheap), but really preferred the cleartops - much easier to come by which is nice when tube rolling. I'm loving the 6CA7 and do not plan on switching. I particulary like them in UL mode. Didn't think I would cause my speakers a bit forward, but right now I'm listening to Wilco's Being There LP (180gram) and its really sweet. Enjoy.
No tube rolling yet. But I am the proud owner of a 2007 TAD-60. The amp is a joy. The biasing is dead simple with the new L.E.D. readouts. I am happily surprised at the quality of the build, even better than the pictures let on.
The amp has the fatboys already installed, the ones that
the other owners have mentioned are a good roll.
But the real treat is the music that this amp can make. It
is quite good. I am the envy of my solid state buddies that try so hard to get that special sound, which this amp does easily.
I also must mention that the TAD is a great value. I haved shopped around and this amp could easily go for double the
price.
So,kudos to Paul and his craftmanship on the TAD-60.
I agree the tad-60 is a great amp, I have a 2006 model (no Led's) I really like my amp, It is now running with SED EL34's a sylvania 5751 for 12ax7 position. and RCA black plate 12au7's. Sounds wonderful biased class a. Just received a set of JJ Kt-77's I will be trying. Paul does a great job. I will also need to try his 6CA7's.
Hey Matman, can you report on the changes you heard with
rolling your 12ax's and the 12au's? I would be interested
in your views.
HI Matman...I have beening running a quad of jj kt77 in triode mode for about a month and I think these are the best yet with good tight base and mids like the el34. I also replace the ax7 with jan 5751 and with these changes, I think the amp sounds better than ever...How has your experience with the kt77 gone?....Same question for anyone elso also
Larry, would you describe the difference between the 77s from 6ca7s . I'm running two Tad-60s to VMPS RM40s.
Thanks. Stan
I've been listening to my 60 for about two months now - almost 4 hours daily. I've determined that in my setup using the Chinese 6L6GC's from Paul produce a better mid and upper midrange than the 6CA7's. Can't tell about the lower end since I use a sub and don't worry about it. If you all haven't tried that quad of tubes (set up for class A) try it. I think you will be pleasantly surprised.
For those of you interested in PRaT (pace, rhythm and timing), how does this amp do in that regard?

Mike
Depends what tubes you use. I use the EH 6CA7 and the attack is very fast. This amp sounds better with every improvement that I have made. I recently bought some very thick speaker cable which opened up the amp even more. It has made the biggest difference with more air, the musical components are spread out across the room and front to back... Still has not seemed to reach its potential...
Hi Stan.....I have tried the 6ca7, kt 90, el34....And think the kt77 just have a nice balance tight bass and ratain the lush midrange of the EL 34 valve....I also rolled in a jan 5751 in ax7 position and this seemed to further the improvement...I just don't have a real desire to roll anymore tubes....That's kind of unusual for our hobby...I also run a pair of spendor s5e speakers and get around this combo...Just sounds right to me