Building a symmetrical psu B1 buffer

[Salas]

The CCS kills the ripple. Its a matter of other characteristics that may manifest subjectively. Mainly the quality of the caps. Don't go over 10mF for each, and find a way not to introduce appreciable cabling. 4700uF is more than enough IMO, just get best quality.

[samoloko]

thx Salas

I am following your advices - now my system Is on Hi end state

thank you

[le´flu]

Hello everybody,
i just finished the B1 project.
But one question is left....maybe i over read it
but what´s the ideal idss for the sk170 on b1?

Greetings Ulf

[Salas]

There is no ideal. BL grade.

[Algar_emi]

Hi. I almost completed my Mesmerize and just a few questions:

What IDSS current do you recommend for the B1 matched quad 2SK170BL?
I have a great range I can choose from from about 6.34 to 10.50ma

Is it necessary to match some of the Shunt Reg 2SK170 FET, or I can use any IDSS current I want? Match per section, per side, etc...

What is the Led Vforward I need to match for the LED used in the Shunt Reg section? Is it 1.8V? What circuit do you use to match them, serie resistor, supply voltage, etc? Or do you match them into the circuit?

I don't have the BC517 (Darlington NPN transistor) use for the relay drive. Can I use some other transistor, is it necessary to have a darlington there?
I have BC550, BC547, BD139, BDX53C, MPSA06, ZTX450 (all NPN, but I also have their complement as well) in stock. Any of these could do the job?

Thanks in advance.
SB

[Salas]

Originally Posted by Algar_emi

Hi. I almost completed my Mesmerize and just a few questions:

What IDSS current do you recommend for the B1 matched quad 2SK170BL?
I have a great range I can choose from from about 6.34 to 10.50ma

Is it necessary to match some of the Shunt Reg 2SK170 FET, or I can use any IDSS current I want? Match per section, per side, etc...

What is the Led Vforward I need to match for the LED used in the Shunt Reg section? Is it 1.8V? What circuit do you use to match them, serie resistor, supply voltage, etc? Or do you match them into the circuit?

I don't have the BC517 (Darlington NPN transistor) use for the relay drive. Can I use some other transistor, is it necessary to have a darlington there?
I have BC550, BC547, BD139, BDX53C, MPSA06, ZTX450 (all NPN, but I also have their complement as well) in stock. Any of these could do the job?

Thanks in advance.
SB

7-10mA will do. Whatever you have plenty. Normally around 8-8.5 most matches occur.

You can match those under the 5 string leds that see ground through 10Rs. The others no. Use what does not match mostly so to utilize.

1.8Vf are mostly ok. 1k resistor and a 9V battery.

You can use BC550. If you experience relay chatter, it happens sometimes with just NPNs, use a Miller cap of 100-150n between B,C of the coil driver NPN. BC517 does not present that problem with any relay.

[Algar_emi]

Thanks for the fast and very useful reply.

[paul.42]

hi all i've ordered a pr of hypnotise boards,i would like to to build a balanced pair,what if any, parts would i change todo this and what values would they change to,thanks in advance..

[Peppe]

Hi all,

may I ask 2 basic questions?

1) Do I have just parallell the inputs RCAs for a tape-loop output?

2) Nobody has already tested Sowter 3575 trafo for bal ins and outs?

Thanks

[Salas]

Originally Posted by paul.42

hi all i've ordered a pr of hypnotise boards,i would like to to build a balanced pair,what if any, parts would i change todo this and what values would they change to,thanks in advance..

Never done it. But I think its a matter of connecting them up right to the XLRs than changing anything in the design.