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Re: Dynaco ST-70 Kits??

I have an ST70 with the Triode Electronics board and another ST70 that has been rebuilt to stock specs with 1% metal film resistors. the resistors are of the same brand used in the Triode board. The coupling caps are identical and both have had their bias and power supplies rebuilt to identical specs. Both ST70's are identical to each other except for the driver boards.
First let me say that there is NO comparison between an un-rebuilt ST70 and a stock rebuild like mentioned above. The updated resistors and caps yield a much more accurate and fast presentation. The un-rebuilt amp lacks speed and detail. Some of the original carbon comp resistors can be 30% out of spec. When brought into spec with tight tolerance parts, the ST70 comes to life.
In comparing the Triode board ST70 and the stock ST70, I find them to be nearly indistinguishable from each other. This is exactly as the Triode Electronics board is designed to sound. The stock 7199 front end tubes are fussy and prone to failure. There is also a big difference between brands of 7199's. RCA 7199 are an absolute must for the ST70, but they are getting rediculously priced if you can find them at all. The three tube Triode Electronics board accomplishes the same sound, but with available cheaper tubes.
If I were to choose one for listening to the rest of my life, it would be the T.E. version as it allows a great deal of modification with various output tubes.
If I were to choose for resale, It would be the stock ST70.
I have recently purchased an ST70 board of stock circuit design etched on fiberglass. You may have seen them for sale on E-Bay recently. I'll procure some NOS RCA 7199's and give it a try in yet a third ST70 that I've owned for a while, but done nothing with other than get it working. Yes, I'm an ST70 Hog. It will probably sound identical to the other two, but I guess I'll see.
Regards:
Paul Keller pkeller@ix.netcom.com


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  • Re: Dynaco ST-70 Kits?? - pkeller 11/21/0123:04:55 11/21/01 (0)


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