Burning Amp BA-3b (Balanced)

[Zen Mod]

you got me there,

was too fast

 

[dodovouk]

Not so fast. 10Vpp or less is more likely since 28V is at the gate of cascode transistor and 20-30V drop across drain load resistor from 30ma bias.

I am getting 44v p2p now with the standard Burning Amp 3 gain board and rail of 48v dc, why do you say I will only get 10v ?

 

[indra1]

Please calculate operating points or do simulation to understand. The circuit has to be modified to meet output level and gain that you need, but then it may have high distortion. I do not see a good solution coming from that scheme for you.

 

[dodovouk]

Please calculate operating points or do simulation to understand. The circuit has to be modified to meet output level and gain that you need, but then it may have high distortion. I do not see a good solution coming from that scheme for you.

I proposing to put a more powerful gain/pre amp with 60v gain

 

[indra1]

There are ImPasse Preamplifier with ImPasse Preamplifier thread by SY and Pumpkin preamp - More Boring Making Thread by ZM that may suit your need better.

 

[neno70]

hi, I was completing the assembly of the components on the pcb of the Burning Amp BA-3 as a guide 6L6, now, I saw this thread on the balanced version, coreggetemi if I'm wrong, in case I wanted to build the version b changes to remove the resistors R5 from 100 Ohm on both channels of the BA-3 board and join them with a 200 ohm resistor? connect the positive input to a channel, the negative to the other channel, mass in common? and at the output of the 2 pcb of power one the positive speaker and the other the negative speakers? quite right ?

 

[Zen Mod]

picture is confirming your questions ......

shorter - yes

 

[neno70]

well, one last question; I already have a 1000w 2x18v transformer, but it will not be enough to feed both channels, right?

 

[Zen Mod]

it depends - how deep you want to set Iq

with 18Vac secondaries , count on 22-23Vdc after rectification and filtering ...... say that you choose 150W of heat per (balanced) channel ..... that's 300W of heat for stereo

1KW will suffice , if Donut is not ringing and buzzing

so , try it

 

[neno70]

it depends - how deep you want to set Iq

with 18Vac secondaries , count on 22-23Vdc after rectification and filtering ...... say that you choose 150W of heat per (balanced) channel ..... that's 300W of heat for stereo

1KW will suffice , if Donut is not ringing and buzzing

so , try it

 

[dodovouk]

There are ImPasse Preamplifier with ImPasse Preamplifier thread by SY and Pumpkin preamp - More Boring Making Thread by ZM that may suit your need better.

Thanks but it is not going to solve my problem. The output board I have is a current follower which means it will not amplify voltage, only current. I need a pre-amp that outputs 60-70v to9 drive the board well, anything smaller will not do.

 

[dodovouk]

hi, I was completing the assembly of the components on the pcb of the Burning Amp BA-3 as a guide 6L6, now, I saw this thread on the balanced version, coreggetemi if I'm wrong, in case I wanted to build the version b changes to remove the resistors R5 from 100 Ohm on both channels of the BA-3 board and join them with a 200 ohm resistor? connect the positive input to a channel, the negative to the other channel, mass in common? and at the output of the 2 pcb of power one the positive speaker and the other the negative speakers? quite right ?

I am not sure. I am making the single-ended. This is mine. . Can you please show me where did you read about the R5?

 

[Zen Mod]

you were given with recipe few pages back

cascode input stage of BA3 FE , raise rails voltage , and sky is the limit

 

[indra1]

Thanks but it is not going to solve my problem. The output board I have is a current follower which means it will not amplify voltage, only current. I need a pre-amp that outputs 60-70v to9 drive the board well, anything smaller will not do.

ZM answer in post #615 is best for BA3, learn what is needed and post your new schematic here so we can help you. If you want ready made solution then your choice is really limited.
Somebody please correct if I'm mistaken, I think the Impasse can potentially output close to ~40V RMS = 113.2Vpp and the Pumpkin ~20V RMS = 56.6Vpp for a 2 V RMS input and < 1k ohm output impedance.

 

[dodovouk]

ZM answer in post #615 is best for BA3, learn what is needed and post your new schematic here so we can help you. If you want ready made solution then your choice is really limited.
Somebody please correct if I'm mistaken, I think the Impasse can potentially output close to ~40V RMS = 113.2Vpp and the Pumpkin ~20V RMS = 56.6Vpp for a 2 V RMS input and < 1k ohm output impedance.

Thank you so much for your input. Post 6 15 doesn't have anything but if you mean post 616 the schematic, that was posted by me couple of weeks ago. I will definitely Investigate what you talking about the above.

 

[indra1]

Thank you so much for your input. Post 615 doesn't have anything...

This is what I meant.

... cascode input stage and use higher rails

You need to catch up on reading especially the "F5 Turbo" V3 section material to really get what ZM meant.

 

[Zen Mod]

ZM answer in post #615 is best for BA3, learn what is needed and post your new schematic here so we can help you. If you want ready made solution then your choice is really limited.
Somebody please correct if I'm mistaken, I think the Impasse can potentially output close to ~40V RMS = 113.2Vpp and the Pumpkin ~20V RMS = 56.6Vpp for a 2 V RMS input and < 1k ohm output impedance.

regarding old , rails are +/-36V .... so , easy to imagine what output voltage envelope can be ..... well , practically as far you have cojones to go

 

[dodovouk]

regarding old , rails are +/-36V .... so , easy to imagine what output voltage envelope can be ..... well , practically as far you have cojones to go

 

[seanny]

For now you can put a power transformer between your driver and the buffer. Enjoy your music while you come up with a complicated solution.

 

[dodovouk]

For now you can put a power transformer between your driver and the buffer. Enjoy your music while you come up with a complicated solution.

What do you mean?