The Very Best Amplifier I Have Ever Heard!!!!

The plan of the amplifier shows two resistors 15κ-10κ to give result 6Κ who in relation to the resistance value 330Ω give a gain value Χ 18,18 Resistance value 8,2K relation to the resistance value 330Ω give a gain value Χ 24,84 when i put 8,2k i get more wide square wave and the sound more clear/

Any advice please??

Have a look at my post #1776
 
hi there, well done.....it looks great.
Apologies for asking, but do you have a final parts list for the build? I only ask as I bought the boards sometime ago, then suddenly there was alot of do's and do'nts, should be this this way/ or the other, so sadly I lost interest. Today I have log-in after quite some time and spotted your finished Amps..they look great. Cheers, Nicholas
 
hi there, well done.....it looks great.
Apologies for asking, but do you have a final parts list for the build? I only ask as I bought the boards sometime ago, then suddenly there was alot of do's and do'nts, should be this this way/ or the other, so sadly I lost interest. Today I have log-in after quite some time and spotted your finished Amps..they look great. Cheers, Nicholas

Hi Nicholas,

I hope that is all the information here:)

I'm on the board:

C3= 4,7PF
C5 = 10PF
C6 = 4,7PF
C7 = 4,7PF
T7 between B-C: 4,7PF
R20 = 330R (bias 100ma per transistor)

Transformers (TOROIDY.PL Transformatory Toroidalne Producent, Audio, Separacyjne, Trójfazowe, 230/110V, 110/230V, Na zamówienie) : 2x50V/500W (2 bridges for channel)
It is the same 2x50V /500mA for BD249/BD250

from the bottom PCB - 2x 10000/100V.
on PCB - 2x4700/100V.

Best regards.
 

Attachments

  • Schematic.GIF
    Schematic.GIF
    44.2 KB · Views: 1,316
  • PCB.2. Goldmund9.2.pdf
    119.1 KB · Views: 542
  • bom Goldmund 9.2.pdf
    54.3 KB · Views: 425
Last edited:
Hi vitalica,

There is a newer schematic, see blow

Somewhere between page 160-170, this new sch. surfaced. The thing I worried most is the T6 which has its CE 'reversed'. Worth discussion? I had a modified pcb laid for this new sch. too.

BP
 

Attachments

  • GOLDMUND NEW SCHEMATIC PDF..pdf
    121 KB · Views: 618
I thought this one had been nailed a long time ago!

Both orientations result in a forward biased diode, so are equivlent.

The only difference, (not relevant here) is if the polarity is reversed; the top configuration sees a BE reverse zener of about 6.2V, the bottom one whatever VCBo is, which could be high.
 

Attachments

  • diodes.jpg
    diodes.jpg
    100.3 KB · Views: 1,389
Cliff,
what's wrong?

Your 896 by 896 pixel >100kB pic is perfectly visible/legible at the thumbnail resolution of 150 by 150 pixel and just 3.7kB

I do like your explanation of the difference in reverse orientation. 4 ways to connect and 4 different results.

I must be missing something?

Why is the resolution a problem for you? Are you still on dial-up 300baud? :D

"4 ways ..." Not sure what you are getting at! I was trying to show that if the PCB had the transistor inverted it makes no difference since it is used as a forward diode in the CCS tail. So ONE result, not 4.
 
I didn't say it was an issue.
I noted your comments and the fact you were drawing our attention to how the device operates with different orientation and different polarity.

I had not thought that through, as thoroughly, as you have.

Although I didn't use the words. I was in effect thanking you for pointing out the 4 variations rather than just leaving us ignorant of the implications.
 
Golmund clone

Box-transformer
 

Attachments

  • IMGP0909-1.jpg
    IMGP0909-1.jpg
    887.4 KB · Views: 1,174
  • IMGP0915.jpg
    IMGP0915.jpg
    575.9 KB · Views: 258
  • IMGP0914-1.jpg
    IMGP0914-1.jpg
    677.8 KB · Views: 836
  • IMGP0913-1.jpg
    IMGP0913-1.jpg
    775.3 KB · Views: 950
  • IMGP0912-1.jpg
    IMGP0912-1.jpg
    544.7 KB · Views: 1,031
  • IMGP0907-1.jpg
    IMGP0907-1.jpg
    702.8 KB · Views: 441
  • 013.jpg
    013.jpg
    70.2 KB · Views: 535
  • IMGP0892-1.jpg
    IMGP0892-1.jpg
    673.2 KB · Views: 506
  • IMGP0893-1.jpg
    IMGP0893-1.jpg
    676.9 KB · Views: 369
Last edited:
χαλια ... χαλια ...χαλι μαυρο....

( that was cra**y work ... but in plain Greek )

Nick the metal work is a masterpiece and i expect it when painted to look marvelous only i wonder how much of this tank made box will add anything to the sound of your amplifier ....


Your case ( and others also ) should be a subject to the NVA amplifiers article which in a few words said that steel boxes are no good for audio amps , aluminum boxes sound terrible , so they ended up with a plastic box but without screws since screws effect the sound of amp for the worst

Read the article ...it might change your aspect of life ....