Acoustat Model 3 Questions

[Mike Beck]

Vishay GP02 HV Diodes

DigiKey has 3kV and 4kV PIV 250mA diodes:
GP02-40-E3/54 Vishay General Semiconductor | GP02-40-E3/54GITR-ND | DigiKey

 

[john65b]

There is a guy on flea-bay now selling the GP02-40 - tape of 100 for $11 + shipping.

I hope they are not fakes.

 

[sterlingimages]

Can someone show me a pic or a diagram of how to add additional diodes and caps to my mk 121 HV bias section. Do I need to drill additional holes in the board and hard wire the connections. Please give advice and pics if possible.
Thanks

 

[tyu]

Thank Jonn65b for this pic.......good luck

 

[sterlingimages]

So you just add that one 1 diode across the red and white wire without extra cap? That will increase voltage enough to get to 3.2k V.?

 

[sterlingimages]

Sorry I now see the cap thanks makes sense now and I believe the holes are already there. Did you notice the panels easier to drive after doing this? Thanks for the help.
Andrew

 

[tyu]

I have been running my bias high for years.....it opens up the sound....this year i pic up a pr of Acoustat 2+2s I ran them all stock ....with 5k bias that had just been rework with all new parts...for about 4 weeks..then I added the diode an cap....Wow....for me it a must...
I just cant live with the stock setup.... knowing what I was missing.....other may feel diff..
all just one mans finding....good luck

 

[sterlingimages]

Have you bypassed the speaker fuse block, and upgraded the HF caps ? Also using a 14 and 2 ohm resistor in the HF . It's more acuarate.


Thanks again for sharing I'm doing the mod right now with the extra step in the ladder.

 

[sterlingimages]

Soldered on the under side of the board where the traces are a diode going in proper orientation from the white tab from bias transformer to red wire from bias transformer , now do I solder a 3300 pf. Cap along side it from same wires (white and red) as diode? Want to make sure I understand.
Thanks Andrew