conrad-johnson GAT Series 2

[MylesBAstor]

We are excited to announce a redesign of our flagship line-stage preamplifier, the GAT to the GAT Series 2. This update includes the introduction of an improved circuit in the regulator for the main audio power supply. The new regulator also features increased filter capacitance. The power supply main storage continues to feature all CJD Teflon capacitors. The update also includes boosted output coupling capacitance, again using more of the CJD Teflon capacitors. These updates assure that the GAT in its Series 2 incarnation will continue to maintain its leadership position among line-stage preamplifiers

[microstrip]

All I remember was reading that upgrade of the old GAT was possible and would cost around usd 4500.00. Are you going to upgrade yours?

[MylesBAstor]

All I remember was reading that upgrade of the old GAT was possible and would cost around usd 4500.00. Are you going to upgrade yours?

Yes the GAT is going back to cj on Monday; I have to Bob a ring and maybe the Kondo Kagura and preamplifier will spend a little time here while the GAT is visiting Virginia.

The update is $4000 and is quite extensive. New 7DJ8/PC88 tubes replace the original 6922s (whose quality has gone down since the GAT was released 7 (?) years ago), a couple of boards including the PS board are replaced etc. The current list price of the GAT Series 2 is $24,000. (The original was $20K.) cj is known for really only making updates when they think the changes are significant. The ART preamplifier in the 12 years I had it, went through 3 updates and all were definitely worthwhile. As was the change from ART Series 3 to GAT. I had them both here, side-by-side, and the GAT was significantly better. (I couldn't say the same about the ACT preamplifier and was glad I hung onto my ART preamplifier.)

[LL21]

Fantastic news, Myles. What is your best guestimate on what the upgrades will sound like? Any guidance from CJ? Given that everything here seems power related and particularly i note increased capacitance, perhaps even more nimble dynamics, overall dynamic range..and possibly lower noise floor?

[MylesBAstor]

I can add a sentence to the description of the mod. "The work involved is fairly extensive -- it involves installation of a new main printed circuit board, populated with numerous critical parts moved from the original main board, so very labor intensive. I think that's why Bill would have rather had me sell my GAT and just buy a new unit. I thought about it but with products not selling or selling for lot less on audiogon (seems the recession is still there on Audiogon), there was no guarantee of getting my money out.

I think the biggest thing is the tube switch from 6922 to a 7DJ8/PC88. I think the PC88 (and I don't know what brand cj is using but they will only be available to GAT owners) is a far better tube than the 6922 currently being used. The latest batches of 6922 weren't lasting more than 500-750 (est) hours before going noisy. So just based on the PC88, the unit should be quieter and even more transparent than the original model. (of course just a guess.) Some of the PS changes I imagine are being implemented to take full advantage of the PC88 rather than just dropping the tube into a circuit designed for a 6DJ8.

cj also should from I was told last week, be releasing this week a brand new, all tube phonostage. I think cj might be the last company making an all tube phonostage? Then you'll see a new integrated amp from them probably this summer and an exciting new product that I can't reveal winter 2017.

And a warm welcome to our friendly little audio community Lloyd! Nice to have you here!

[microstrip]

The PCC88 shares the same tube specifications as the ecc88/6dj8, except for filament voltage - 7V versus 6.3V. People have found that most power supplies for ECC88 can be easily modified for 7V and many users were for a longtime using expensive brands, such as Telefunken, in their electronics at a fraction of the cost of the ECC88/6dj8 tubes.

Most probably the difference in performance due to tube change is motivated by brand and quality, not the type of tube.

Unfortunately this fact is now common knowledge and prices of the PCC88 are rising!

[MylesBAstor]

The PCC88 shares the same tube specifications as the ecc88/6dj8, except for filament voltage - 7V versus 6.3V. People have found that most power supplies for ECC88 can be easily modified for 7V and many users were for a longtime using expensive brands, such as Telefunken, in their electronics at a fraction of the cost of the ECC88/6dj8 tubes.

Most probably the difference in performance due to tube change is motivated by brand and quality, not the type of tube.

Unfortunately this fact is now common knowledge and prices of the PCC88 are rising!

No doubt the brand of tube was also a consideration. One could get Tele 7DJ8s five years ago for $25 each. Not any more. But as I said, the Q/C of the EH 6922 wasn't what it was when the GAT was released. My first two sets of tubes were fine but the last two sets didn't cut the mustard doing hissy in around 500 hrs. Not to mention one went microphonic. A lot of other GAT owners also experienced the same issues with the Russian 6922s.

Now sometimes you can swap 6DJ8s and 7DJ8s and sometimes you can't. There are a couple of tube designers (for instance I ran into this with my Bottlehead Repro) who use an old trick to reduce noise of running the 6DJ8 at slightly lower than spec'd voltage (I wrote about it years ago in my first Tape Project article). I found at least in the case of the BH Repro, that a 7DJ8 really sounded bad.

[JackD201]

How long will your baby be away Myles? Time for a Doshi Pre review perhaps? If looking for a mid-priced review subject instead of a balls to the wall one I'd nominate the KR P-130. You should check out those proprietary octals they have on there.

[LL21]

Thanks, Myles! Great to be here. and look forward to your comments when your GAT has returned. Both initial comments and of course when properly settled in!

[MylesBAstor]

How long will your baby be away Myles? Time for a Doshi Pre review perhaps? If looking for a mid-priced review subject instead of a balls to the wall one I'd nominate the KR P-130. You should check out those proprietary octals they have on there.

While the GAT is away at the spa, I'll have the Kondo Kagura SE amplifier and Absolare preamplifier visiting. 😄

[JackD201]

Big boy toys!

[ashandger]

While the GAT is away at the spa, I'll have the Kondo Kagura SE amplifier and Absolare preamplifier visiting. 😄

Excellent! Really looking forward to your thoughts on the Kagura especially timbres, microdynamics and bass.

[MylesBAstor]

Yes especially the first two. When I heard it with the S3s, I was very impressed by the amp's/system's delicacy, shadings and low level resolution. How it fares on the low end with larger scale music will be interesting.

[MylesBAstor]

My GAT is off for a spa visit at Canyon conrad-johnson. She'll probably be back in a couple of weeks since the bodywork is very involved. The she'll be burned before returning home freshly manicured.

[Metamatic]

My GAT is off for a spa visit at Canyon conrad-johnson. She'll probably be back in a couple of weeks since the bodywork is very involved. The she'll be burned before returning home freshly manicured.

Looking forward to your thoughts Myles. that is if you can unplug the Kondo

[MylesBAstor]

Ha! It will be interesting to have the two units to listen to and compare and contrast. lt will be a rare pleasure.

There's also one other top notch preamplifier here too!