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Re: Glad to see it finally out there T.

Posted by Thorsten (M) on January 20, 2005 at 03:10:42

In Reply to: Glad to see it finally out there T. posted by jusbe on January 19, 2005 at 17:53:50:

Hi,

> Whilst I remain underdeveloped in the art of DIY,

Something for which easy remedies are readily available....

> And then a nice curry.

Pink Rupee?

> This serial publication reminds me of the best feeatures
> of Sound Practices (popularising lost arts) and Listener
> (enthusing newcomers) combined.

Why thank you. I very much liked both publications and found their demise rather regretable.

> I read comments here in the past about the negative impact
> of 'universality' on any one circuit's optimal performance

I agree that this is there.

I have few doubts that if you develop a given output transformer specifically, strictly and only to complement a given specific valve, that you can get results otherwise not possible. HOWEVER, I know of practically no maker of generically available transformers who does that. In fact, I know even of very commercial makers of gear who do that.

It means in turn that in the key piece of passive component that impacts on the sound all that is being designed for at the transformer maker is in effect turns ratio, primary inductance, leakage inductance and shunt capacitance. Therfore, if you change the impedance of a given transformer by changing taps your performance remains predictable.

As I noted, there are plenty of examples of transformers from well accepted makers which are either "universal" or high impedance with low primary inductance.

> but there seems to be a bigger plan here.

Yes, I had that bee up my bonnet for a long time. In the beginning of the 90's our choice of DHT Outputs was very limited, you had old stock WE300B, new Production Cetron 300B & Chinese Shuang (Gold Dragon) 300B, to that add NOS 2A3's and Chinese Shuang (Gold Dragon) 2a3'S. That was your lot mostly, more excotic stuff was NOS only and even then rare. Low Power stuff like the 45 was largely ignored (45? 1.5Watt? YOU WHAT?).

Now we have from current production (this list is what i readily remember):

TJ 300B (various Types)
TJ 205D
TJ 50
TJ 45
TJ 2A3
TJ PX25
TJ PX4

KR 300B (Various)
KR 2A3
KR PX25
KR PX4

AVVT 300B (various)
AVVT 2A3
AVVT 45
AVVT PX25
AVVT AD1
AVVT various new DHT's

EAT 300B
EAT 2A3
EAT 45

Sovtek/EHX 300B
Sovtek/EHX 2A3

Svetlana 300B

Shuang 300B (various)
Shuang 2A3
Who knows what Shuang will come up with if trnds hold

Add to this the increased breadth and depth of NOS/Used stuff available simply from the presence of E-Bay and the net and you have a huge range of options, all vying for a seat in the output tube socket.

I am sure it would be be great to design and build the optimal amplifier for each, with custom designed outputs and all, but i for one have neither that much time nor that much money.

I had been for the longest time aware of a number of Japanese DIY'ers (and Tube Collectors) whose response to this dilema was to simply make an Amplifier that was easily adjusted (some extremely easy) and I have had previously had my own "universal" Amplifier:

The Legacy Poweramplifier - A "universal" DHT Poweramplifier by Thorsten Loesch .

Despite the various on-line spats caused when I repported comparing 45 vs. 2A3 vs 300B vs. 10Y in this Amplifier it actually worked rather well. Equally, the Fi 2A3 Monoblocks also take 45's. When John Wiesner build 2A3 & 300B Amplifiers to Arthur Loesch's designs they also where somewhat convertible, the 2A3 invariably was 2A3/45 and the 300B invariably was 300B/50/10Y.

All that told me that "universal" Amplifiers can work just fine. So i badgered Brian Cherry for well over 2 years untill he finally relented and got the factory to experiment a little. So, now anyone who likes can buy an Amplifier that can be easily adpated to a wide range of valves.

> invoke anew the oft-dubbed 'Golden Age' of DIY Kit
> experimentation (50s America) for newbies and old hands alike.

Yup.

My point is that you can try whatever takes your fancy. Your friend has a pair of TJ 50's and you wonder if you should give them a try? Simply adjust the Amp and have a listen.

Ciao T

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

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