BoSoZ Gain, P1/P2 etc... Quistion's

[lykkedk]

Hi....

Got some quistion about this BoSoZ / Balanced Line Stage....

I know I had been asking alot about this lately but ----
Simply can't find the right answer for me nowhere !!!

First, I would like to tell how far I got :

I redesigned the PCB for the PSU, so I could use bigger heatsink (Picture's will come next year - !), also for bigger DiodeBridges which I got a lot of, my only consirn is, that they are only 80A !!! each

I have allready tested this PSU, and gives me with my 2x55 vac single transformer 83 - 84 unregulated, and -59 and +60 regulated (Loaded with 15.5k ohm).

I redesigned the PCB Mainboard, for use with some bigger caps (Same value but greater voltage), and for use with 1.5Kohm 11w instead of them 3w 750ohm (R3/R4).
R1 and R2 I use 1.5kohm in parrelel 2w resistors, which gives me about 750ohm 4w...

This I have not finished yet...

I will use this, with my Leach amp 4.5.

I would like to have this straight, When using P1 and P2, I can set the outputvoltage/input BoSoZ of eg. my CD to give max maybe 1.5V at the output of the BoSoZ, when Volume is set to highest (P3/P4) Right ?

Presuming my equipment, gives approxmitaly the same output, there is no need, to use it for normal (My wife/Kids) use Right ?

Actually it could be used as a Volume MAX protection, and balance too. Right ?

I don't understand the meaning of P5, should I use it ?, I was planning to use the P!/P2 and P3/P4, at the front of the Preamp, and short the P5, but I don't know, The best performance is 10dB, so how do I obtain this 10dB without P5.

I will use stereopot P1/P2 and stereopot P3/P4 (Volume)

Should I just short R14, and use +in and GND ? and use +out and ground for output
?, when using it unbalanced, this could be done with an extra switch on the line in selector, so i could have maybe CD, DVD, PC, and and extra for the future -Balanced for an DAC maybe ?
The balanced line in then put's in the R14 instead of an short when using it unbalanced.

LOOT'S of quistion I know thanx anyway..

 

[Mad_K]

Hi....


I would like to have this straight, When using P1 and P2, I can set the outputvoltage/input BoSoZ of eg. my CD to give max maybe 1.5V at the output of the BoSoZ, when Volume is set to highest (P3/P4) Right ?

yes

Presuming my equipment, gives approxmitaly the same output, there is no need, to use it for normal (My wife/Kids) use Right ?

yes

Actually it could be used as a Volume MAX protection, and balance too. Right ?

yes

I don't understand the meaning of P5, should I use it ?, I was planning to use the P!/P2 and P3/P4, at the front of the Preamp, and short the P5, but I don't know, The best performance is 10dB, so how do I obtain this 10dB without P5.

make r15 about 430 ohm, and don't use p5.

I will use stereopot P1/P2 and stereopot P3/P4 (Volume)

Should I just short R14, and use +in and GND ? and use +out and ground for output
?,

yes

when using it unbalanced, this could be done with an extra switch on the line in selector, so i could have maybe CD, DVD, PC, and and extra for the future -Balanced for an DAC maybe ?
The balanced line in then put's in the R14 instead of an short when using it unbalanced.

this is also how I do it

 

[lykkedk]

Re: Re: BoSoZ Gain, P1/P2 etc... Quistion's

Thanx you great Norweigan, that's all I want to know. GODT NYTAAR...

 

[ElectroNick]

Output pot value

Hello all,

at last.... the PCB's are finished and ready to test
But, what value should the output pot have ?
Is the 5k from the article the best choice when connected to the Aleph 5 (yes allmost finished too)

I'm thinking of using fixed input values. Those stereo pots are too expensive (if you would use DACT ) or are there better options ?

Gr,
Nick

 

[Mad_K]

I'm using DACT CT2-4-10k as output pot, fixed input. If you are driving an aleph, and use good interconnects, it is no worry (the 10k versus 5k halves the high frequency roll-off point).

 

[ElectroNick]

Hi Mad,
Did you use 10k and 221e for the input ?

Gr,
Nick

 

[Mad_K]

i used 22,1k, but 10k is also just fine.

 

[lykkedk]

By the way, should I use linear or ulinear stereopots ?

 

[Bricolo]

always logarithmic ones, for audio use

 

[lykkedk]

OK Thanx !