Review: Tube Audio Design TAD-1000 Tube amp


Category: Amplifiers

I bought a pair of Paul Grzybek's TAD-1000 Monoblocks about five months ago. Since then I've had a few queries on how I liked them so I thought I would post my own notes on setting them up along with a brief review. Hopefully, my system and experiences are enough different from others that this is worthwhile.

Setup

Follow Paul's directions. You definitely want to take your time in setting the bias and feedback and selecting your 'normal' listening mode - Triode (3) or Pentode (4). You have to do the bias first, of course (350-370 on all four on each amp after a 10-minute minumum idle warm-up). After that I would recommend that you set the feedback to mid-range of the knob travel. Pick your normal mode (Triode or Pentode) by switching the mode while you are listening to some well-known music. Then set the feedback on both monoblocks while listening to some familiar music.

I find I like the detail and clarity of the Triode wiring but others prefer the punch and boost of the Pentode mode. There are certain recordings that sound better with Pentode - some of the older Beatles stuff comes to mind. But, I usually leave the monoblocks set to Triode and just turn them up a bit, even when listening to something like Led Zepplin, instead of switching to Pentode - but you definitely get more power in Pentode. The feedback setting makes a LOT of difference in how the harmonics affect the sound reproduction. It's a trade-off. Adjust them until things sound true-to-life to your ear. You will want to do this with different types of music and music passages. It is probably best to use vocal, piano, and other mid-range passages to fine-tune the feedback settings. You will likely find that the perfect setting for one passage is not the same as the perfect setting for another recording or passage. It will also probably depend on the source. What's nice about the 1000's is that Paul gives you control of this trade-off instead of using a built-in setting.

For the gain controls on the back of the monoblocks, I would set them to just a bit off of full open - crank them all the way up and then back off about an 1/8th of a turn. I make this recommendation not out any specific technical basis, but just on my own belief that it is not a good idea to have any control set all the way to the stops as a permanent state of affairs. I use the gain controls in my own set up as a method of balancing the sound stage in my particular listening area.

Results

Once you've set up, you can start listening with a fair degree of musical pleasure. Break-in was noticeable but fairly short-lived. I would say not more than a few hours. During that time I did notice a few overly bright spots and some passages that sounded a bit 'jangly,' if that makes any sense to you. But nothing was persistently noticeable. After that short period, things have been very, very good in the listening department.

Bass is immediate and full. I have a home theater system with a subwoofer and a solid-state AV amp (Harmon-Kardon AVR520, Polk Audio RM-7 5.1 speaker system). I output from the Denon source to both the home theater system via a fibre-optic digital audio cable and to the stereo system via right-left RCA cables. For those of you not familiar with the Soliloquy 5.3 speakers, see specs below - they are not big thumpers. The bass through these speakers with the stereo setup rivals the bass of the home theater system - even at the vibrate-the-walls, impact-tremor level that is more felt than heard. This was so surprising to me that I toyed with the idea of getting rid of the home theater system and just using the stereo system for all sound reproduction. But, the home theater does offer the center speaker that makes dialog come through with such clarity - that and the surrond-sound effects make it worth keeping.

For the mid-range, vocals and piano, etc., the sound is right there. You can listen to Norah Jones, for example, close your eyes and imagine that you are sitting at a table right in front of the stage. Highs come through pure and bright and clear, without being obnoxious. The sound stage is broad and pervasive. I can sit at my desk across the room and to the side of the system's normal listening area and still enjoy music with very little reduction in the presence of the sound stage.

After having these TAD-1000's for a few months now, I can say I am more than happy with them. There are always improvements that can be made, but the addition of these monoblocks has given me my holy grail of sound. Well, at least for the time being. ;-)

Associated gear
Tube-Audio Design TAD-150 tube preamp with signature mods by Paul Grzybek

Soliloquy 5.3 Speakers - Each speaker has two 5 1/4" drivers and one 1 1/8" tweeter and is floor-standing with spikes.

Analog Source - Music Hall MMF-9

Digital Source - Denon 3910 with mods by Mike Powell (HRAM)

Similar products
Acoustic Sound Labs AQ-1006 845 monoblocks
bamabubba
You mention at the bottom of your post the Antique sound labs 845s - is this a comparison? Did you have a pair of these or are you saying that they may be similar in type?
Thanks for the review, I've had my mine for 1 1/2 weeks now and like what I'm hearing so far. I'm also using mine with the Tad-150 Signature preamp. I do think the break in for these may last a little longer then you stated. weather real or imagined mine continue to sound better each day I listen to them but then again I just purchased a used pair of Quad EL21's that are only four months old used exclusively in an apartment and don't think are fully broken in yet. You can only listen to music so loud in those confines without making enemies or being evicted. These speakers are just "stupid good" for the money and so far this has been a great combo. I currently prefer listening in the pentode mode but that may change but all the standard audiophile terms apply here: great soundstaging, depth, imaging and did I mention good tight bass that is more then adaquate for my 20x18 room. It's way too soon to give a formal review but I think Paul's got a winner here. BTW I was also wondering if anyone had tried using kt88 tubes and if so how they sound.

Ken
While it is far too soon to do a full evaluation, having the amps just about two weeks, my experience mirrors that of Bamabubba. So far my preferences have been for triode mode, with the feedback control one click to the right of center.

At this time, however, I am not the best one to discuss break in.

I recently received my upgraded Von Schweikert speakers back from the factory (VR 4 to 5/7 "Pheonix" upgrade), and although I am past the intial phase, they are still breaking in themselves. BTW, Albert Von Schweikert and his staff also represent the best in customer service, like Paul with his products, they want to ensure that you get the most out of them. (Great sound, great service, reasonable price. That is real value). The speakers started to sound great with my older tube amps, but with the TAD-1000s they are crossing into "amazing" territory.

I am not an audio newbie, and have listened to and evaluated many products and systems over the years, and have learned to be cautious with praise. Over the years, I have experienced the feeling of being "blown away" a few times, by equipment that seems to do more than incrementally improve on the competition, and brings the sense of of a live event much closer. However, sometimes, after further listening, flaws are revealed and the equipment does not seem quite so great.

After living with both admittedly only a short time, collectively, the VR Pheonix mod speakers and the TAD-1000 monoblocks together represent the former experience (blown away), with no hint yet of the latter (disenchantment). In fact the sound may be getting better (or as my friend Harvey says, I am getting used to it).

A few weeks ago, while in Chicago, my wife and I caught a performance of the Chicago Symphony with Charles Dutoit. Seats were pretty good (lower balcony, near center). Whenever I attend a live performance, perhaps like many an audiophile I make mental note of the characteristics of the sound. I was surprised (pleasantly) by how remarkably well some of the classic Reiner-Layton-Mohr recordings in that venue sounded (Get the JVC XRCDs, if you can). These recordings are well know to most audiophiles (Scheherezade, Lt. Kije, etc.). My updated system was able to mimic most of the characteristics of that hall with startling veracity. Tonally, instruments sound like themselves. There is a mountain of "air." Background quiet (after around 9:00 PM, anyway) is eerie. You can hear all of the slight, normally obscured, rustling sounds made by the musicians.

Only in the dynamic domain does the system fall short. However, DO NOT take that as a critisism of the system. The system provides a "sense" of the dynamics far better than most I have heard. But, I have never heard any system capable of replicating the dynamic reality created by the CSO in Orchestra Hall, and I doubt one (for the home) exists. Or, perhaps the recordings do not capture the full dynamic range. I leave that discussion to experts.

This is not a review. Just early feedback. Perhaps I will say more when the system is fully broken in, whenever that is (how does one know?).

I am curious if other owners have compared the sound of the TAD-1000s with EL34s versus KT88s, 6550s or KT90s. I wonder if 6L6s work? Some folks love that tube.

A special "Thank you" goes to Sandy from Levyphoto.com, one of the top sellers of specialty tubes on Ebay, and another great guy, whose trained ears helped me get the amps set up, and whose GOLD PIN Ei ELITE GRAY PLATE 12AX7 tubes really, really sweetened the sound. Amazing! Sandy, I will be ordering more, and am looking forward to trying your KT77s.

And another thank you to friend and old tube equipment guru Harvey R. for keeping me grounded, and providing technical guidance.
While it is far too soon to do a full evaluation, having the amps just about two weeks, my experience mirrors that of Bamabubba. So far my preferences have been for triode mode, with the feedback control one click to the right of center.

At this time, however, I am not the best one to discuss break in.

I recently received my upgraded Von Schweikert speakers back from the factory (VR 4 to 5/7 "Pheonix" upgrade), and although I am past the intial phase, they are still breaking in themselves. BTW, Albert Von Schweikert and his staff also represent the best in customer service, like Paul with his products, they want to ensure that you get the most out of them. (Great sound, great service, reasonable price. That is real value). The speakers started to sound great with my older tube amps, but with the TAD-1000s they are crossing into "amazing" territory.

I am not an audio newbie, and have listened to and evaluated many products and systems over the years, and have learned to be cautious with praise. Over the years, I have experienced the feeling of being "blown away" a few times, by equipment that seems to do more than incrementally improve on the competition, and brings the sense of of a live event much closer. However, sometimes, after further listening, flaws are revealed and the equipment does not seem quite so great.

After living with both admittedly only a short time, collectively, the VR Pheonix mod speakers and the TAD-1000 monoblocks together represent the former experience (blown away), with no hint yet of the latter (disenchantment). In fact the sound may be getting better (or as my friend Harvey says, I am getting used to it).

A few weeks ago, while in Chicago, my wife and I caught a performance of the Chicago Symphony with Charles Dutoit. Seats were pretty good (lower balcony, near center). Whenever I attend a live performance, perhaps like many an audiophile I make mental note of the characteristics of the sound. I was surprised (pleasantly) by how remarkably well some of the classic Reiner-Layton-Mohr recordings in that venue sounded (Get the JVC XRCDs, if you can). These recordings are well know to most audiophiles (Scheherezade, Lt. Kije, etc.). My updated system was able to mimic most of the characteristics of that hall with startling veracity. Tonally, instruments sound like themselves. There is a mountain of "air." Background quiet (after around 9:00 PM, anyway) is eerie. You can hear all of the slight, normally obscured, rustling sounds made by the musicians.

Only in the dynamic domain does the system fall short. However, DO NOT take that as a critisism of the system. The system provides a "sense" of the dynamics far better than most I have heard. But, I have never heard any system capable of replicating the dynamic reality created by the CSO in Orchestra Hall, and I doubt one (for the home) exists. Or, perhaps the recordings do not capture the full dynamic range. I leave that discussion to experts.

This is not a review. Just early feedback. Perhaps I will say more when the system is fully broken in, whenever that is (how does one know?).

I am curious if other owners have compared the sound of the TAD-1000s with EL34s versus KT88s, 6550s or KT90s. I wonder if 6L6s work? Some folks love that tube.

A special "Thank you" goes to Sandy from Levyphoto.com, one of the top sellers of specialty tubes on Ebay, and another great guy, whose trained ears helped me get the amps set up, and whose GOLD PIN Ei ELITE GRAY PLATE 12AX7 tubes really, really sweetened the sound. Amazing! Sandy, I will be ordering more, and am looking forward to trying your KT77s.

And another thank you to friend and old tube equipment guru Harvey R. for keeping me grounded, and providing technical guidance.