Peter,
My only reason to want to use 4 gang pot instead of two 2 gang pot is that I don't want to have to spend 5 minutes (exaggerated of course!) adjusting the level of each channel before I sit down to listen to music.
I'm not familiar with DAC1 connections. I'll take a look at it. Thanks.
My only reason to want to use 4 gang pot instead of two 2 gang pot is that I don't want to have to spend 5 minutes (exaggerated of course!) adjusting the level of each channel before I sit down to listen to music.
I'm not familiar with DAC1 connections. I'll take a look at it. Thanks.
For those of you who don't want to decipher the D1
schematic, the pots were set up as variable resistance
between the outputs of the balanced channel. This
loads down the outputs which are out of phase to
theoretically 0, saving you a pot.
However, the two halves have to be driven by a perfectly
matched balanced signal and also have to be matched
pretty well if you want the volume to go to Zero.
If not, the volume gets down low, but never quite reaches
total silence. You can, of course, trim the channels into
matching to get this.
schematic, the pots were set up as variable resistance
between the outputs of the balanced channel. This
loads down the outputs which are out of phase to
theoretically 0, saving you a pot.
However, the two halves have to be driven by a perfectly
matched balanced signal and also have to be matched
pretty well if you want the volume to go to Zero.
If not, the volume gets down low, but never quite reaches
total silence. You can, of course, trim the channels into
matching to get this.
Thanks Nelson .... and Peter for bringing up this idea. Now let me see if I know what I'm looking at ..........
====The D1 schematic shows a 22K pot with a 4.7uf at the + side ====
Peter or anybody ..... please review the following to make sure that I got it right. Thanks.
1. For the BOSOZ, I guess I should buy a 5K pot since the article mentioned 5K pot? If I can't find 5K, would 10K do? Do I need to install the 4.7uf capacitor? What is the purpose of the capacitor anyway? If I do need it, what size and voltage rating?
2. For installation: For each channel, I connect the pre-amp Vout(-ve) to the Input of the pot and the Vout(+ve) to the output of the pot? Is the polarity correct as I indicated? And there is no ground connection on the pot since "this is set up as variable resistance between the output of the balanced channel"?
Note:
If what I described above is correct, I could just add another 2 gang 5K pot to the output and keep the other two 2 gang 10K pot that I have already on the board and have the flexibity - just as Nelson described in the article - to adjust the input and output any which way I like!
====The D1 schematic shows a 22K pot with a 4.7uf at the + side ====
Peter or anybody ..... please review the following to make sure that I got it right. Thanks.
1. For the BOSOZ, I guess I should buy a 5K pot since the article mentioned 5K pot? If I can't find 5K, would 10K do? Do I need to install the 4.7uf capacitor? What is the purpose of the capacitor anyway? If I do need it, what size and voltage rating?
2. For installation: For each channel, I connect the pre-amp Vout(-ve) to the Input of the pot and the Vout(+ve) to the output of the pot? Is the polarity correct as I indicated? And there is no ground connection on the pot since "this is set up as variable resistance between the output of the balanced channel"?
Note:
If what I described above is correct, I could just add another 2 gang 5K pot to the output and keep the other two 2 gang 10K pot that I have already on the board and have the flexibity - just as Nelson described in the article - to adjust the input and output any which way I like!
fcel,
1 the pot should be prefferably 5k or less. Personally I would not put 10k, it's slightly too high at the output. The cap at the output is to block 30V DC. You have to use it. Something around 5uF and voltage around 100V (higher voltage caps sound better). Put there something good because it affects sonics. I like Hovland Musicaps mixed with MIT RTX but they cost money.
I have a question for all: Did anybody tried Black Gates non polar NX caps in that location. I bought some 4.7u at $5 ea. but didn't try them yet. Some people say they better than any film cap.
2. Your are correct here. It doesn't really matter where pos and neg side go.
3You can do that, but I would drop one pot, remember they affect sonics. Only one at the output should be fine.
1 the pot should be prefferably 5k or less. Personally I would not put 10k, it's slightly too high at the output. The cap at the output is to block 30V DC. You have to use it. Something around 5uF and voltage around 100V (higher voltage caps sound better). Put there something good because it affects sonics. I like Hovland Musicaps mixed with MIT RTX but they cost money.
I have a question for all: Did anybody tried Black Gates non polar NX caps in that location. I bought some 4.7u at $5 ea. but didn't try them yet. Some people say they better than any film cap.
2. Your are correct here. It doesn't really matter where pos and neg side go.
3You can do that, but I would drop one pot, remember they affect sonics. Only one at the output should be fine.
Peter,
Thanks for your response.
My last paragraph is probably misleading. What I meant was I'll be installing only ONE 2 gang pot at the output. Correct? And I'm going to leave the TWO 2 gang pot that were already installed at the input unchanged.
I forgot to ask. Do you know who sells 2 gang 5K pot? Michael Percy Audio? I've heard that it's hard to get.
Thanks for your response.
My last paragraph is probably misleading. What I meant was I'll be installing only ONE 2 gang pot at the output. Correct? And I'm going to leave the TWO 2 gang pot that were already installed at the input unchanged.
I forgot to ask. Do you know who sells 2 gang 5K pot? Michael Percy Audio? I've heard that it's hard to get.
If you don't need them, remove them. I mean 2 2gang pots at the input. All pots degrade sound so why keep them?
Michael Percy sells only 10k pots. I don't know where to find 5K.
I will be installing switched attenuator at the output.
In the meantime you can install one of your 2 gang pots at the input the same way you plan to do the output and see how it works.
Michael Percy sells only 10k pots. I don't know where to find 5K.
I will be installing switched attenuator at the output.
In the meantime you can install one of your 2 gang pots at the input the same way you plan to do the output and see how it works.
Sadly, you are probably reading the prices right!
My idea is to use something like a six position rotary switch with 6 resistors, on the input and gain positions, to give coarse control over those functions, maybe first use a cheap potentiameter to get the best values first.
USe a switched Dact control on the output.
The Dact switched wolume controls seem to be the best design,
and one of the cheaper ones. If put across the outputs so we only need stereo, would cost about $140 from aloha audio.
http://www.aloha-audio.com/#dactintro
Thats almost reasonable for a switched volume control!
Only seems to come in 10k though. Maybe we couldgroup order a batch of 5k
Hey all you passive preamp guys, can't we bridge the 10k pot with a resistor to make it more like a 5k? If so what resistor?
My idea is to use something like a six position rotary switch with 6 resistors, on the input and gain positions, to give coarse control over those functions, maybe first use a cheap potentiameter to get the best values first.
USe a switched Dact control on the output.
The Dact switched wolume controls seem to be the best design,
and one of the cheaper ones. If put across the outputs so we only need stereo, would cost about $140 from aloha audio.
http://www.aloha-audio.com/#dactintro
Thats almost reasonable for a switched volume control!
Only seems to come in 10k though. Maybe we couldgroup order a batch of 5k
Hey all you passive preamp guys, can't we bridge the 10k pot with a resistor to make it more like a 5k? If so what resistor?
This is what I'm using. Elma on the left can be bought from Michael Percy for $57 (BV22568). With 24 positions and special contacts for audio it's not bad. I used it in my DAC and it works fine. All you need is 50 resistors. In my premp I would probably use Electro Switch on the right. But I don't know where to get it.
Attachments
Where to get it
http://www.partsconnexion.com/catalog/controlsswitches_files/sheet002.htm (this seems to send you to the wrong place -- some weird parsing on this board, go to www.partsconnexion.com and dig down
)
This is the phoenix of www.sonicfrontiers.com/tpc, most probably run by the same people -- certainly most of the same products.
And it is in Canada
Petter
http://www.partsconnexion.com/catalog/controlsswitches_files/sheet002.htm (this seems to send you to the wrong place -- some weird parsing on this board, go to www.partsconnexion.com and dig down
)This is the phoenix of www.sonicfrontiers.com/tpc, most probably run by the same people -- certainly most of the same products.
And it is in Canada
Petter
Where to get it
And if you have problem getting it from partsconnexion try: http://www.percyaudio.com
And if you have problem getting it from partsconnexion try: http://www.percyaudio.com
I bought a DACT CT-2 from Rolph at www.audiocomponents.nl and landed it cost $80. U.S., good service and excellent prices on drivers etc.
Tony D.
Tony D.
Harry: Excuse us for going off the subject here .... but in any case, BOZ or BOSOZ requires at least one 2 gang pot.
Tony: I assume your DACT CT-2 is not used for the output of BOSOZ because it's not available in 5K. But ..... $80 is cheap .... I think!
Peter: I assume the Elma (BV22568) is not 5K either but it is so called 2 gang and sells for $57? Where do you get information on how to wire up those 50 or something resistors and what values of the resistors? I hope it comes with instructions.
Anybody: As previously posted by Mark and I wanted to know too .... where can one get 5K pot? 2 gang, switched attenuator or whatever you call it. Thanks in advance.
Tony: I assume your DACT CT-2 is not used for the output of BOSOZ because it's not available in 5K. But ..... $80 is cheap .... I think!
Peter: I assume the Elma (BV22568) is not 5K either but it is so called 2 gang and sells for $57? Where do you get information on how to wire up those 50 or something resistors and what values of the resistors? I hope it comes with instructions.
Anybody: As previously posted by Mark and I wanted to know too .... where can one get 5K pot? 2 gang, switched attenuator or whatever you call it. Thanks in advance.
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