Goldmund Wiki and build 2017

[daltvi]

They sell printed circuit board + N ° 4 jfet5566 are the originals and fundamental for the sound performance + Bill of material + schematic + photo

 

[daltvi]

GM 27 MPSA42 and MPSA92 Motorola

may i ak, where you got the pcb´s from?

I want to buy the original Motorola MPSA42 and MPSA92 transistors where can I find them?

 

[daltvi]

may i ak, where you got the pcb´s from?

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

I want to buy the original Motorola MPSA42 and MPSA92 transistors where can I find them?

 

[wesayso]

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.

I certainly do adore it!

My reference amplifier – Vandermill-Audio

Telos 400 clone

 

[jensenhoffman]

Hi
Has anybody tried the lsk489 dual j-fet as a replacement for the 2N5565?

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.

 

[quanghao]

I've been making this amplifier for years, you can check it out here:

 

[keantoken]

Congratulations, it looks great.

 

[quanghao]

Congratulations, it looks great.

Thank you so much. you are one of the people who helped me complete this amplifier.
you run the LTspice simulation well and it's awesome.
Quanghao

 

[daltvi]

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

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

 

[Mooly]

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

 

[Sensation45]

Has anyone tried 2n5401/2n5501 instead of gm29 a mpsa92/42?

 

[Sensation45]

2n5551 to the input I marked... Double mpsa42/92 to the other output

 

[fencki]

here is my clone of goldmund...

 

[Sensation45]

here is my clone of goldmund... View attachment 1089189

#Fencki Thank you, very nice, did you use the mpsa92/42 signal transistors?

 

[Sensation45]

here is my clone of goldmund... View attachment 1089189

How about 2sk176 2sj56 in 2 pairs of images goldmund 29 a

 

[fencki]

#Fencki Thank you, very nice, did you use the mpsa92/42 signal transistors?

yes

 

[fencki]

How about 2sk176 2sj56 in 2 pairs of images goldmund 29 a

View attachment 1089228 View attachment 1089229

did not try that

 

[Silvio Novais]

here is my clone of goldmund... View attachment 1089189

✅ Hi! Where can I buy a Goldmund kit just like yours?
I don't need cabinets or transformer.

 

[alex mm]

My Goldmund amplifier from 2013 , PCB layout by me !

Alex

 

[Sensation45]

My Goldmund amplifier from 2013 , PCB layout by me !

Alex