Goldmund Wiki and build 2017

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#503
fencki said:
may i ak, where you got the pcb´s from?
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finwbu said:
Hi,

I build up two GM27 preamps using Motorola MPSA42 & MPSA92, the one i build without machting the offset on the output was 60mV - 70mV what is pretty high. So matching the MPSA is needed at least they are used in the Current Mirrors. When i build with the matched MPSA offset was 5mV to 10mV without for touching the offset pots.

Br Walter
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I want to buy the original Motorola MPSA42 and MPSA92 transistors where can I find them?
 
#504
koldby said:
I made a clone of a Telos 350-400 and it sounds great, (sold it, but am in contact with the owner, who adores it) and it has never failed.
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I certainly do adore it!

My reference amplifier – Vandermill-Audio

Vandermill-internals.jpg

Telos 400 clone
 
#505
koldby said:
Hi
Has anybody tried the lsk489 dual j-fet as a replacement for the 2N5565?
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I did.

I've tried 2N556X, LSK389 and LSK489.
Their soundstage differed for sure.
It's just matter of taste.

I'd prefer 389 and 489.

But don't anticipate LSK489 with darker background since it's advertized as "low noise". It is just a small part of the entire amplifier.
 
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#509
finwbu said:
Boccadoro 27 Costruzione fai-da-te

Ciao,

Ho costruito due preamplificatori GM27 usando Motorola MPSA42 e MPSA92, quello che ho costruito senza modificare l'offset sull'uscita era di 60 mV - 70 mV che è piuttosto alto. Quindi è necessario abbinare l'MPSA almeno vengono utilizzati nei Current Mirrors. Quando costruivo con l'offset MPSA abbinato era compreso tra 5 mV e 10 mV senza toccare i potenziometri offset.

Fra Walter
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Ho terminato la costruzione del preamplificatore GM mimesis 27 ho un problema a cui non riesco a trovare la soluzione. Il volume di uscita dal GM mimesis 27 è molto alto. Quando si ruota la manopola del volume di alcuni gradi di circa 10 gradi, il volume è molto alto e difficile da regolare, basta ruotarlo un po' e il suono viene amplificato enormemente. ho selezionato abbinato i transistor Motorola Mpsa42 e Mpsa92. Come mi ha fatto notare il venditore della carta, ho anche regolato gli offset DC. La tensione di alimentazione jn VCC +/- 53V. Potenziometro Alp 10 + 10K.

Aspetto un consiglio
 
#510
:cop:

English please. Rules.

I have finished the construction of the GM mimesis 27 preamplifier I have a problem to which I can not find the solution. The output volume from GM mimesis 27 is very high. When you turn the volume knob a few degrees by about 10 degrees, the volume is very high and difficult to adjust, just turn it a little and the sound is amplified enormously. I selected paired the Motorola Mpsa42 and Mpsa92 transistors. As the card seller pointed out to me, I also adjusted the DC offsets. The supply voltage jn VCC +/- 53V. Potentiometer Alp 10 + 10K.

I look forward to a tip
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