Review: Tube Audio Design TAD-1000 Tube amp


Category: Amplifiers

The amps under review here, the TAD-1000’s are built in China and are hand finished in the USA by one Paul Grzybek, an audio good guy if ever there was one, of BizzyBee Audio in Chicago. Weighing in at a substantial 43lbs each, the amps are nicely finished with a thick black anodized face plate and a lovely brushed stainless steel chassis. The transformers are carefully finished with stainless steel covers. The indicator lights are located front and center and are bright blue, really bright blue! The amps come well packed in solid Styrofoam containers that even FedEx can’t damage. Your amps will arrive in one piece.

The tube complement consist of an EH 12AX7 input tube feeding a pair of EH 6V6GT’s. The output is handled by a matched quad of new Tung-Sol 6550’s for 100 watts per amp. Each amp has an input level control on the back panel, a variable feedback control, set at about 50%, and a triode/UL switch. The amp is 60 watts in triode mode. All listening was done in UL mode which sounds better to these ears. For this review all tubes were stock except for the input tubes which I replaced with a NOS pair of RCA “Cleartop” 12AU7’s, which I find more harmonically rich and detailed than the stock EH 12AX7’s.

Setup and biasing are easy. Each tube is individually biased (to 650mv for 6550 or KT-88 and 350mv for EL-34’s) with top mounted access points and bias adjustments using the supplied multimeter. The entire process took about 90 minutes from start to finish.

Once setup, the amps were run-in for 50 hrs before any serious listening. The majority of this time was filled with home theater uses, which provided the majority of the break-in listening.

As is my usual practice, vinyl represented the source material for this review. The material used for this review includes:

Holst: “The Planets” Mehta LAPO Decca SXL6529
Schubert: “Symphony # 5” Sound 80 DD
Copland: “Appalachian Spring” Reference RR-22
“Cantate Domino” Proprius 7762 White Jacket
Ravel: “Alborado Del Gracioso: Classic Records test pressing 45rpm LSC2222 45
Stan Getz/Joao Gilberto: “Getz/Gilberto” Verve810 048-1
Vince Guaraldi: “Jazz Impressions of Black Orpheus” Fantasy 3337
Harry James: “The King James Version” Sheffield Lab-3
Rickie Lee Jones: “Rickie Lee Jones” Warner BSK 3296
Bob Marley and the Wailers: “Survival” Island LPS 9542
David Bowie: “Changes Bowie” Ryko Analogue RALP-0171-2
Suzanne Vega: “Suzanne Vega” A&M SP6-5072

My initial impression of the 1000’s is one of great harmonic accuracy. On the Holst disc, the string tone is gorgeously reproduced, while the richness of the choir is exemplary. The same can be said for the other classical discs. All were reproduced with a sense of tonal accuracy and harmonic realism that I failed to get from my PS Audio 100C.
If you’re familiar with “Cantate Domino” on Proprius than you know that it recreates the ambience of the church with unusual precision. The TAD’s reproduce this ambience with great specificity, one can hear the stone walls of the church; the effect is eerie and moving. All of this is accomplished without blurring or muddying the vocal or instrumental lines on this outstanding album. Generally I can state that these amps have a very nice way with the harmonic structure of orchestral instruments, reproducing the wood, rosin, brass and drums with natural and believable felicity.

Dynamics seem limited only by the speakers and the room. The amps go on and on dynamically. These amps are exceptionally good at going from ppp to fff quickly and decisively. Ravel’s “Alborado” on Classic Records 45rpm single-sided pressing is awesomely dynamic, a new reference IMO. Compared to the PS Audio, the TAD’s reproduce the dynamic shadings and movement in a more natural manner, without moving the stage either forward or back. The music gets louder without a marked change in positioning, a rare occurrence on LP’s and an effect that doesn’t happen to live instruments.

Imaging is another strong suit of the amps, as one might expect from monos. The Getz/Gilberto disc was exemplary in this regard with the placement of Getz’s sax and Astrud Gilberto’s voice each occupying their own specific space. That space is maintained at different volume levels and dynamic shadings, very nice indeed. The Harry James is big band at its best. Well recorded and quietly pressed, rare for Sheffield’s IMO, this album maintains the sound of a big band with suitably biting brass, reedy, sax sounds and richly harmonic reproduction of the entire band. The drum solo on track 3 “Cherokee” is as well sized as any that I have heard, it is reproduced quite convincingly.

“He who feels it, knows it” so sang Bob Marley’s widow Rita. On Bob’s album “Survival” one feels and hears the emotional content and message on such songs as “Zimbabwe”, “Africa Unite”, “One Drop” and “Ride Natty, Ride” in a way that allows the listener to “know” Bob feels it in a way, though hard to describe, that is more personal than before, more immediate and heartfelt through these amps.

The mystique of tubes remains despite the “antiquated” technology. Big, heavy and hot, tube amps enjoy a place in the High-End for one reason; they arguably reproduce the sound of music more realistically than transistors do. The TAD-1000’s represent an amazing combination of value and sonics that one will, IMO, be hard pressed to find anywhere else. These are not the best amps on the planet but they are damned good. Any flaws represent flaws of omission. The top might be a little softer than real, the stage a little forward, and I do mean a little forward. These are things I can easily live with given the otherwise insanely good qualities of the amps.

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risabet
I followed the directions precisely. In fact, when I set up the amps I had the bias control set at the top of its range and I watched the meter. When it went too high I turned the control to the opposite stop and the bias was set very low. At that point I continued with the set-up, as per instructions, and had no problem at all.
How efficient are you ML Speakers? What kind of load do they present to the amp? Did you play with the variable negative feedback settings?

Thanks.
The ML are 89dB/meter efficiency with an average load of 4 ohms with a dip to 1.2 ohms at 20kHz. Not a problem as there is hardly any musical energy up there to worry about.
Eldartford, I asked Paul the same question. The 2 black "transformers" are just covers for the power supply caps.