Hey Thanks...
Sorry I didn't respond to your post right off. I read it, and it's just sunk in now. Gives me where to play with stuff from here...
Thanks
PeaceandMusic
Sanaka
Sorry I didn't respond to your post right off. I read it, and it's just sunk in now. Gives me where to play with stuff from here...
Thanks
PeaceandMusic
Sanaka
FINALLY!
My search is over! After spending the last few days scouring the web for info regarding DIY passive volume controllers I have finally arrived at this great forum which, for me, is nothing short of a relative Holy Grail! Although many of my questions / concerns have been thoroughly answered in this thread, I am hoping that someone might help me with a few more details.
Firstly, I am not an engineer, electrician, etc. so I am having some trouble understanding the schematics that accompany many of the great explanations / instructions in this thread. I am sure they are probably straight forward to many of you folks but they are greek to me! Show me a detailed photo on the other hand...
So far, this is what I have been able to glean from this thread - please let me know where I am off base:
FROM THE RCA CHASSIS INPUT SOCKET TO THE POT: Positive lead (red) to the pot's "eye" 1, negative lead (black/ground) to pot's "eye" 3.
FROM THE POT TO THE RCA CHASSIS OUTPUT SOCKET: Postive lead (red) to pot's "eye" 2, negative lead (black/ground) to pot's "eye" 3.
If this is correct, at what jucture do I place the resistor(s)? Are they placed in the red leads (one lead or both) or in the ground leads (one or both)? Is it O.K. to have the grounds simply connected to the RCA chassis sockets or should they also be connected to chassis itself?
Also, my volume control setup is for my video audio only so I will not be using switches or tape inputs/outputs. The video audio, however, is surround and the inputs/outputs will consist of Front L/R, Center and Rear L/R. I would like to control the fronts and rears as one channel, i.e., do not want a pot for the Front left and one for the Front right, for example. Would I use a dual-gang pot for the front and rears in this case while using a mono for the center?
And finally, If I wanted to control all five channels simultaneously (once I had the fronts, center and rears adjusted) would I need a 5-gang pot?
Thanks a million for any input you may have and thanks even more for this great forum! BTW, I came across a couple of DIY passive amp photos and it does not appear that the builders incorporated resistors as shown below.
My search is over! After spending the last few days scouring the web for info regarding DIY passive volume controllers I have finally arrived at this great forum which, for me, is nothing short of a relative Holy Grail! Although many of my questions / concerns have been thoroughly answered in this thread, I am hoping that someone might help me with a few more details.
Firstly, I am not an engineer, electrician, etc. so I am having some trouble understanding the schematics that accompany many of the great explanations / instructions in this thread. I am sure they are probably straight forward to many of you folks but they are greek to me! Show me a detailed photo on the other hand...
So far, this is what I have been able to glean from this thread - please let me know where I am off base:
FROM THE RCA CHASSIS INPUT SOCKET TO THE POT: Positive lead (red) to the pot's "eye" 1, negative lead (black/ground) to pot's "eye" 3.
FROM THE POT TO THE RCA CHASSIS OUTPUT SOCKET: Postive lead (red) to pot's "eye" 2, negative lead (black/ground) to pot's "eye" 3.
If this is correct, at what jucture do I place the resistor(s)? Are they placed in the red leads (one lead or both) or in the ground leads (one or both)? Is it O.K. to have the grounds simply connected to the RCA chassis sockets or should they also be connected to chassis itself?
Also, my volume control setup is for my video audio only so I will not be using switches or tape inputs/outputs. The video audio, however, is surround and the inputs/outputs will consist of Front L/R, Center and Rear L/R. I would like to control the fronts and rears as one channel, i.e., do not want a pot for the Front left and one for the Front right, for example. Would I use a dual-gang pot for the front and rears in this case while using a mono for the center?
And finally, If I wanted to control all five channels simultaneously (once I had the fronts, center and rears adjusted) would I need a 5-gang pot?
Thanks a million for any input you may have and thanks even more for this great forum! BTW, I came across a couple of DIY passive amp photos and it does not appear that the builders incorporated resistors as shown below.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
hmm it's hard for me to tell from your description but that doesn't sound quite right.
i will reference the pot's leads like this: look at the pot head-on, from the knob side, with the connection leads facing down. from left to right, the pins are 1, 2, and 3.
first, connect the resistor from the INPUT center pin to the OUTPUT center pin. this is the series resistor which forms the signal path.
second, wire the OUTPUT center pin (where the resistor just went) to PIN 1 of the pot.
third, wire PIN 2 of the pot to GROUND. all grounds are tied together (INPUT, OUTPUT, and pot).
that should take care of it. pin 3 of the pot is left unused, or you may tie it together with pin 2 to minimize noise.
test it very carefully, preferrably into another working preamp or volume control, to make sure you wired it right. if something is reversed you could end up blasting a full-scale signal into your amp, or get a very loud hum. set it fully counterclockwise, then slowly turn up your other safety volume control to be sure the signal is properly attenuated. once you are sure there is no signal or noise, slowly operate your new passive preamp with the other preamp at low volume to be sure everything is ok.
you will need a 5 gang pot to control 5 channels as you say.
cheers,
marc
i will reference the pot's leads like this: look at the pot head-on, from the knob side, with the connection leads facing down. from left to right, the pins are 1, 2, and 3.
first, connect the resistor from the INPUT center pin to the OUTPUT center pin. this is the series resistor which forms the signal path.
second, wire the OUTPUT center pin (where the resistor just went) to PIN 1 of the pot.
third, wire PIN 2 of the pot to GROUND. all grounds are tied together (INPUT, OUTPUT, and pot).
that should take care of it. pin 3 of the pot is left unused, or you may tie it together with pin 2 to minimize noise.
test it very carefully, preferrably into another working preamp or volume control, to make sure you wired it right. if something is reversed you could end up blasting a full-scale signal into your amp, or get a very loud hum. set it fully counterclockwise, then slowly turn up your other safety volume control to be sure the signal is properly attenuated. once you are sure there is no signal or noise, slowly operate your new passive preamp with the other preamp at low volume to be sure everything is ok.
you will need a 5 gang pot to control 5 channels as you say.
cheers,
marc
Can this L-pad be substituted for a dual-gang pot given the same shunt designs outlined in previous posts?
Impedance: 8ohms, watts: 10-25
Impedance: 8ohms, watts: 10-25
An externally hosted image should be here but it was not working when we last tested it.
...and also I think we where talking about line level attenuators here with shunting in the 1-25 k range. 8 Ohms and the L-pad I think is for level adjustment of speakers at loudspeaker levels and likewise currents.
/UrSv
/UrSv
So much for L-pads! After re-reading the item description for the pictured item it became clear that it was for use between the amp and the speaker - not the source and the amp.
Thanks again.
Thanks again.
Rather than use Radio Shack parts for my passive, I did a web search in an effort to find (what I hoped to be) better quality components.
Suprisingly, this proved to be a daunting task given my search results seemed to terminate in either very expensive, reference audio parts or quality brand parts sold only in lots of 500. Hopes of one-stop shopping for pots, resistors, solder, sockets, etc. seemed futile.
After a dozen toll-free calls across the country, I finally reached a kind soul that pointed me in the direction of a supplier that he thought might meet my needs. Get a load of this... the guy he pointed me to was a friend of mine and used to live down the road!
Anyway, my friend's name is Mike and his home business is Mike Percy Audio (percyaudio.com). Mike has absolutlely everything under one roof and his prices are very competitive! BTW, I am in no way affiliated with Mike's business; just thought that I would pass this along in an effort to spare some other newbie hours of fruitless web surfing.
To Marc: thanks a million for your patience and detailed guidance with regards to my project - you are the best!
Suprisingly, this proved to be a daunting task given my search results seemed to terminate in either very expensive, reference audio parts or quality brand parts sold only in lots of 500. Hopes of one-stop shopping for pots, resistors, solder, sockets, etc. seemed futile.
After a dozen toll-free calls across the country, I finally reached a kind soul that pointed me in the direction of a supplier that he thought might meet my needs. Get a load of this... the guy he pointed me to was a friend of mine and used to live down the road!
Anyway, my friend's name is Mike and his home business is Mike Percy Audio (percyaudio.com). Mike has absolutlely everything under one roof and his prices are very competitive! BTW, I am in no way affiliated with Mike's business; just thought that I would pass this along in an effort to spare some other newbie hours of fruitless web surfing.
To Marc: thanks a million for your patience and detailed guidance with regards to my project - you are the best!
whoa!
whoa! you know michael percy? he's been my one and only source for so many "audiophile" parts for years now. he is our parts savior! that's pretty funny you didn't even know he sells parts. you should have no problem getting what you need now i imagine. i wish michael percy was my friend. damn you.
whoa! you know michael percy? he's been my one and only source for so many "audiophile" parts for years now. he is our parts savior! that's pretty funny you didn't even know he sells parts. you should have no problem getting what you need now i imagine. i wish michael percy was my friend. damn you.
HarryHaller,
I am looking to upgrade my diy Rat Shack preamp. I am very happy with your design, and I have a few questions.
Do you prefer your Alps Black Beauty 100k pot with the Caddock 10 resistor or your 50k lin Bourns pot with 9k one watt glass Corning resistor?
Would gold plated jacks be worth an upgrade if I'm using a cheap rat Shack 8 phono board?
Where should I get the silver wire?
How should I decide whether to use a lin or log pot and a 10k 50k or 100k pot?
With a linear pot is law-faking config necessary?
Thanks,
Ryan
I am looking to upgrade my diy Rat Shack preamp. I am very happy with your design, and I have a few questions.
Do you prefer your Alps Black Beauty 100k pot with the Caddock 10 resistor or your 50k lin Bourns pot with 9k one watt glass Corning resistor?
Would gold plated jacks be worth an upgrade if I'm using a cheap rat Shack 8 phono board?
Where should I get the silver wire?
How should I decide whether to use a lin or log pot and a 10k 50k or 100k pot?
With a linear pot is law-faking config necessary?
Thanks,
Ryan
I just started this DIY control center (passive pre). I used the radio shack autoformer volume control ($30) and removed the autoformers from the pc board. I bought a vintage decade resistor on ebay. I took the switches out, removed the resistors, hooked them to the autoformers and now I easily have the best volume control I have ever heard in 17 years of working in audio (I have not heard the transformer volume controls yet). This thing is better than amazing. It has no business being this good. I listen to music very late at night so I took the first two extra contacts and added resistors to give me very low volume levels. I will be using the other two switches from the decade resistor to independently source select.
By the way, it is connected to a Sony SCD-CE775 SACD player and the ASL wave 8 mono amps. For a total of right under $500. Just add speakers.
Try it and you will just shake your head.
By the way, it is connected to a Sony SCD-CE775 SACD player and the ASL wave 8 mono amps. For a total of right under $500. Just add speakers.
Try it and you will just shake your head.
Attachments
dorkus said:
Well I know...yes it is....it's better than the best pot. Alps, P&G, Noble name one... it's better, unless you like not hearing everything your source can deliver. Um then it isn't.
why's it better man?
And how does it work? Maybe you could break it down a bit for the newbies. How might one go about doing their own one of these?
PeaceandMusic
Sanaka
And how does it work? Maybe you could break it down a bit for the newbies. How might one go about doing their own one of these?
PeaceandMusic
Sanaka
I still have a few questions about where to take my passive preamp from here, and I would appreciate help from HarryHaller or anyone else.
HarryHaller,
I am looking to upgrade my diy Rat Shack preamp. I am very happy with your design, and I have a few questions.
Do you prefer your Alps Black Beauty 100k pot with the Caddock 10 resistor or your 50k lin Bourns pot with 9k one watt glass Corning resistor?
Would gold plated jacks be worth an upgrade if I'm using a cheap rat Shack 8 phono board?
Where should I get the silver wire?
How should I decide whether to use a lin or log pot and a 10k 50k or 100k pot?
With a linear pot is law-faking config necessary?
Thanks,
Ryan
HarryHaller,
I am looking to upgrade my diy Rat Shack preamp. I am very happy with your design, and I have a few questions.
Do you prefer your Alps Black Beauty 100k pot with the Caddock 10 resistor or your 50k lin Bourns pot with 9k one watt glass Corning resistor?
Would gold plated jacks be worth an upgrade if I'm using a cheap rat Shack 8 phono board?
Where should I get the silver wire?
How should I decide whether to use a lin or log pot and a 10k 50k or 100k pot?
With a linear pot is law-faking config necessary?
Thanks,
Ryan
ryan,
most of your questions should be answered if you read through the thread again. i would upgrade the phono jacks to something better. also, any good wire will work fine, doesn't have to be silver and the exact type is a matter of personal preference - i'd hesitate to call a particular wire "better" than another. i personally like Cardas litz, 30 gauge or so. you can get everything you need from Michael Percy Audio. (www.percyaudio.com). again, most of this info is already in the thread.
dorkus
most of your questions should be answered if you read through the thread again. i would upgrade the phono jacks to something better. also, any good wire will work fine, doesn't have to be silver and the exact type is a matter of personal preference - i'd hesitate to call a particular wire "better" than another. i personally like Cardas litz, 30 gauge or so. you can get everything you need from Michael Percy Audio. (www.percyaudio.com). again, most of this info is already in the thread.
dorkus
law faked shunt = problem
What Musiclover4 asks that I think is NOT in this thread, explicitly, is what's up with simultaneously using BOTH law fake AND a shunt design, the latter being the thrust of HH's originating post. I tried it, and it doesn't work "that way." I am a rank newbie, so there's probably something I should have gotten that I didn't, but here's basically my standing on this project: I had a linear pot on hand, and did the shunt, a la HH and this thread, and that was quite nice. So naturally the next improvement was the law fake, a la the Elliot Sound Products website, which shows a resistor (1/6.67 x pot resistance), branching to ground off the wire which goes from the pot to the RCA out jack. So this is where I stuck my resistor too. D'OH! Obvious to the less obvious-challenged here is that this simply provides an extra route for the signal to be shunted by - my signal was super attenuated (and I reverted to the shunt only).
Law fake as shown at ESP is for a traditional series pot. There seems to be no analogous place to put a law-fake resistor in a shunted configuration.
But I don't know anything 😱
For a shunt design, is a log pot the only way to have a log taper? Given a linear pot, can one implement BOTH law fake AND shunt at the same time?
PeaceandMusic
Sanaka
What Musiclover4 asks that I think is NOT in this thread, explicitly, is what's up with simultaneously using BOTH law fake AND a shunt design, the latter being the thrust of HH's originating post. I tried it, and it doesn't work "that way." I am a rank newbie, so there's probably something I should have gotten that I didn't, but here's basically my standing on this project: I had a linear pot on hand, and did the shunt, a la HH and this thread, and that was quite nice. So naturally the next improvement was the law fake, a la the Elliot Sound Products website, which shows a resistor (1/6.67 x pot resistance), branching to ground off the wire which goes from the pot to the RCA out jack. So this is where I stuck my resistor too. D'OH! Obvious to the less obvious-challenged here is that this simply provides an extra route for the signal to be shunted by - my signal was super attenuated (and I reverted to the shunt only).
Law fake as shown at ESP is for a traditional series pot. There seems to be no analogous place to put a law-fake resistor in a shunted configuration.
But I don't know anything 😱
For a shunt design, is a log pot the only way to have a log taper? Given a linear pot, can one implement BOTH law fake AND shunt at the same time?
PeaceandMusic
Sanaka
dorkus,
I have read and reread the thread many times (at least 10). I even printed it off because I got so sick or reading it over and over on my computer.
My dad has some 99.9 percent 30 gauge copper wire that he said is supposed to be very good so I guess I'll probably just use that if silver wire isn't always considered much better.
I think sanaka summed up my final questions pretty well, becuase I haven't quite figured out if law-faking config with a linear pot and a shunt design can coexist, and how to optimize sound quality while still having a smooth volume control that has decent range. It seems like the best bet would be to just get a stereo Alps Black Beauty 100k log pot and not deviate much from the design since I don't really know what I'm doing.
I have read and reread the thread many times (at least 10). I even printed it off because I got so sick or reading it over and over on my computer.
My dad has some 99.9 percent 30 gauge copper wire that he said is supposed to be very good so I guess I'll probably just use that if silver wire isn't always considered much better.
I think sanaka summed up my final questions pretty well, becuase I haven't quite figured out if law-faking config with a linear pot and a shunt design can coexist, and how to optimize sound quality while still having a smooth volume control that has decent range. It seems like the best bet would be to just get a stereo Alps Black Beauty 100k log pot and not deviate much from the design since I don't really know what I'm doing.
Hey Musiclover4 hang in there-
You have to understand that sound quality of a passive preamp (or any component) is very subjective. I have not made any measurements on the passive preamp I bulit but I have a few others preamps to compare the sound with and on that basics (I think) the sound quality is very good.
Also I didn't really plan for Law faking with Linear or Audio pots with caddocks resistors and special wire, I just used whatever I had left over from some parts changes I had from some other projects. And I got lucky.
So if you want to play around with different designs, you may have to do most of the work your self as in tracking down designs and expermenting. Check some of the earlier threads I posted. I know I listed a web site that has design info of passive preamps. And my pessive preamp volume didn't increase much past 3:00 position.
Handmade Electronics has good prices on silver wire at www.hndme.com
😎
You have to understand that sound quality of a passive preamp (or any component) is very subjective. I have not made any measurements on the passive preamp I bulit but I have a few others preamps to compare the sound with and on that basics (I think) the sound quality is very good.
Also I didn't really plan for Law faking with Linear or Audio pots with caddocks resistors and special wire, I just used whatever I had left over from some parts changes I had from some other projects. And I got lucky.
So if you want to play around with different designs, you may have to do most of the work your self as in tracking down designs and expermenting. Check some of the earlier threads I posted. I know I listed a web site that has design info of passive preamps. And my pessive preamp volume didn't increase much past 3:00 position.
Handmade Electronics has good prices on silver wire at www.hndme.com
😎
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