I agree Moe, (i'm building the BoSoZ too)
Vince, if you want to do some tweaking you could always "X" the BoSoZ. (search for Henrik on this forum and you'll find the schematic)
Good luck with building...
ps watch out for the size of heatsinks in the power supply. If you use the power board, the space on it is too small. My heatsinks reach allmost boiling temperatures
Grtz,
Nick
Vince, if you want to do some tweaking you could always "X" the BoSoZ. (search for Henrik on this forum and you'll find the schematic)
Good luck with building...
ps watch out for the size of heatsinks in the power supply. If you use the power board, the space on it is too small. My heatsinks reach allmost boiling temperatures
Grtz,
Nick
My BZLS (or BOSOZ) PCB is on the way. Can anyone who has built one share how you use your level control? The original design can use either on the input side or on the output side!
One diyer told me he put on both input and output, but he did not see any benefit with it and suggest me use the input side. Any thought of this?
Also, do I really need to use the expensive 4 decks attenuator (like the DACT CT2-4) for a balanced stereo output. What's the cheaper solution, yet provide reasonable good sound?
Thanks
Thomas
One diyer told me he put on both input and output, but he did not see any benefit with it and suggest me use the input side. Any thought of this?
Also, do I really need to use the expensive 4 decks attenuator (like the DACT CT2-4) for a balanced stereo output. What's the cheaper solution, yet provide reasonable good sound?
Thanks
Thomas
vdi_nenna said:Put the control on the output, so noise is also lowered when you adjust for the volume.
vdi- bad idea. You wind up effectively raising the output impedance severely. That's why volume controls are put before the circuit in these things.
Nelson prefers the pot on the output side .A solution would be to get two Alps blue velvet and rig them up with a gear link.Cheaper than the 200usd dact.I think a member posted some pictures here of a set up like that.tomchaoda said:My BZLS (or BOSOZ) PCB is on the way. Can anyone who has built one share how you use your level control? The original design can use either on the input side or on the output side!
One diyer told me he put on both input and output, but he did not see any benefit with it and suggest me use the input side. Any thought of this?
Also, do I really need to use the expensive 4 decks attenuator (like the DACT CT2-4) for a balanced stereo output. What's the cheaper solution, yet provide reasonable good sound?
Thanks
Thomas
A simple sollution?
Gear - links...getting too advanced.
There should be better/easier ways to lower the gain.
A pot. at the output is ok, but still I think the BoSoZ has too much gain, and the output pot. makes it somewhat system dependable.
(needs a high input-impedance power-amp; ZapPulse is a no-no).
I have read reports that lowering it too much w. R-15 also affects sound quality.
Other sollutions?
Arne K
Gear - links...getting too advanced.
There should be better/easier ways to lower the gain.
A pot. at the output is ok, but still I think the BoSoZ has too much gain, and the output pot. makes it somewhat system dependable.
(needs a high input-impedance power-amp; ZapPulse is a no-no).
I have read reports that lowering it too much w. R-15 also affects sound quality.
Other sollutions?
Arne K
Try this:
Put a pot at the input to adjust the level of the incoming signal such that the output level stays in the 'sweet spot' (lowest distortion; iirc this was about 1v p-p output).
Then put a lower valued pot (5k or so) at the output to adjust the volume, lower the noise, etc.
Put a pot at the input to adjust the level of the incoming signal such that the output level stays in the 'sweet spot' (lowest distortion; iirc this was about 1v p-p output).
Then put a lower valued pot (5k or so) at the output to adjust the volume, lower the noise, etc.
I would start by using pots suggested by Nelson, adjusting them for proper value, then measure and insert fixed resistors.
You could probably also get away with increasing input imp pot value up to 30k or so, and decreasing output pot's value to less than 1k, for better imp matching.
You could probably also get away with increasing input imp pot value up to 30k or so, and decreasing output pot's value to less than 1k, for better imp matching.
Hi Vince,
the BOSOZ is a very good preamp with pleny of room for improvement, namely X, full dual mono, CCS, superregs (all coming up soon for mine) and that is going to keep you happy, and busy for a long time.
If you bought the PCB from old colony be gentle, the traces are rather flimsy and they are a one time solder pretty much. Try to increase all the heatsinks and solder the 750 ohms resistors away from the pcb as they get HOT.
I would play with the gain and pots before boxing everything up. You'll probably find that the four dec stepped attenuator is a more pricy but convenient solution, let's face it, unless you like playing with knobs and continuoulsy adjusting levels all over the place you need to limit yourself to one knob.
I have two pots and since they are not perfect, I have to play with levels to get the right image from the speakers everytime I want to hear a song louder.
I am soon going with the remote control unit and a 0.1% resistor ladder.
the BOSOZ is a very good preamp with pleny of room for improvement, namely X, full dual mono, CCS, superregs (all coming up soon for mine) and that is going to keep you happy, and busy for a long time.
If you bought the PCB from old colony be gentle, the traces are rather flimsy and they are a one time solder pretty much. Try to increase all the heatsinks and solder the 750 ohms resistors away from the pcb as they get HOT.
I would play with the gain and pots before boxing everything up. You'll probably find that the four dec stepped attenuator is a more pricy but convenient solution, let's face it, unless you like playing with knobs and continuoulsy adjusting levels all over the place you need to limit yourself to one knob.
I have two pots and since they are not perfect, I have to play with levels to get the right image from the speakers everytime I want to hear a song louder.
I am soon going with the remote control unit and a 0.1% resistor ladder.
balanced volume control
Hi,
since I´m also thinking of building an X-BOSOZ I had a look at the different options for a balanced (output) volume control.
The most obvious choise would be a ladder configuration with a 4 deck elma 24 step selector. This is quite expensive and very big!
Then I found another sollution on the Borbely homepage, a balance ladder output control wich by design is perfectly balanced. It is here:
http://www.borbelyaudio.com/index8.htm
It´s much simpler and you only need a normal two deck switch.
I think it is perfectly suited for the BOSOZ.
william
Hi,
since I´m also thinking of building an X-BOSOZ I had a look at the different options for a balanced (output) volume control.
The most obvious choise would be a ladder configuration with a 4 deck elma 24 step selector. This is quite expensive and very big!
Then I found another sollution on the Borbely homepage, a balance ladder output control wich by design is perfectly balanced. It is here:
http://www.borbelyaudio.com/index8.htm
It´s much simpler and you only need a normal two deck switch.
I think it is perfectly suited for the BOSOZ.
william
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