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.

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

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ggeers222
I've recently installed the Penta KT88s in my TAD 60 and had a similar experience with high bias readings. The V1, V2 & V4 sockets all rose quickly to the 580 range while the V3 went all the way up to 620. After about 15 minutes at idle, the V1,2 & 3 settled in at approx. 525, while the V3 settled at 585. I'm new to tube power amps so this was pretty scary since I couldn't get down to that recommended 200 starting point but I emailed Paul and he said not to be too concerned unless the readings hit the 700 mark. They never did and all seems well after a couple days.

Dave
Paul has some new bias settings on his site that should be worth trying. The new settings will provide Single Ended Class A for the first 10 watts and Class A/B for 10-50 watts.
Dave, I'm using the Penta 88's also and find them to be a good sounding tube. What are your impressions?
Jeff
Jeff,

I've got only about 15 hrs. on the Pentas but I really like what I'm hearing so far. From top to bottom they are an improvement over the EL34s with great balance and more articulate bass so I'm looking forward to what 50+ hrs. on them will bring. Do you know if Paul's single-ended class A bias is adaptable to the KT88s or is it just for the EL34s?
Dave,

From the bias levels it would be used for the EL34's. I did try it with my stock tubes & it did sound nice. Especially in the mids. Worth a try. Nice to have alternatives.

Jeff
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?