Does anyone know what would be the effect on the circuit if I were to use an RK27 10k pot for the volume control. The pot I have now doesn't have matched attenuation at the lower limits. They advertise a 5K version of the RK27 but you can't find anywhere to order. So what are the thoughts on this?
Ok so from reading the first version of this pre was with a 10k volume pot. He goes into explanation about the three types of loading associated with the pot. About the only thing it might do is a very slight increase in johnson noise due to higher resistance. but the design is very low in noise to begin with and the inclusion of the dual buffer after volume that he upgraded on ver2 cuts back on some of that noise by 3dB anyway. Worth a try. my concern was would it have any issues with changing response of tone controls but that is a no.
Oh BTW does the pot have to be linear in the active volume circuit? Or can it be log like the RK27, maybe a show stopper?
A logarithmic taper won’t hurt anything. It imparts a small change in the overall attenuation curve, and log pots tend to be less precise in curve and channel matching. The Baxandall volume control with a linear potentiometer will track more accurately than an average log pot, but gets very loud quickly in the first 10-15% of volume knob rotation, so it may not suit every systems’ gain structure. It gives a lot of control from 0dB down to -30dB, then attenuates really quickly down to minimum.
I am new to all of this so if I break any kind of protocol, please excuse. Is there any way to still get one of these kits? Or PCB artwork, or Gerber file, or parts list? I did not read all of the pages of this thread, but it is clear that it represents a pretty amazing (and years long) effort. I am currently reading Douglas Self and am very impressed. Would very much like to try this project. Thank you.
Reading the first page and post is important. Mr. Huff sadly passed away last year so this design is not available. He sold the pcbs/parts? to members and did not make the pcb fab files available.
Wish we could keep it alive. somehow for the community.
As the title says, the design article is available in volume 5 of Linear Audio.
Wish we could keep it alive. somehow for the community.
As the title says, the design article is available in volume 5 of Linear Audio.
Hello.
Sometime ago (as Carl was relocating from California) I processed an order for boards and have some spares. He permitted me to resell extras to dyiaudio members (IE not eBay) but I have never got around to it. They are black with white silkscreens. I also have a few of the Tayda pots available.
PM me and perhaps we make some arrangements.
Sometime ago (as Carl was relocating from California) I processed an order for boards and have some spares. He permitted me to resell extras to dyiaudio members (IE not eBay) but I have never got around to it. They are black with white silkscreens. I also have a few of the Tayda pots available.
PM me and perhaps we make some arrangements.
This community needs to figure a way to keep these boards alive? I do not know if there are owners to the Gerbers but possibly this could be transferred to the DIYaudio store? This just such a fine preamp and a fully realized effort. Mine looks like something you could purchase from a hi end company. Would like to know what people think?
I agree with @Freecrowder - This is a very nice project worthy of sustaining.
Hi @Sumaco - Do you have Gerber files for the boards? If yes, could you offer a group buy and have one of the fab houses in China print the boards?
Hi @Sumaco - Do you have Gerber files for the boards? If yes, could you offer a group buy and have one of the fab houses in China print the boards?
As far as I can tell, Carl never released the fab files since he was selling kits. I assume the family has no interest in releasing them so it’s back to square one.
My suggestion is that if folks want to recreate the design, it’s best to do it in kicad.
Make a list on who wants one, if it’s sizeable, I could look into getting it off the ground. It’s a great way to learn kicad
My suggestion is that if folks want to recreate the design, it’s best to do it in kicad.
Make a list on who wants one, if it’s sizeable, I could look into getting it off the ground. It’s a great way to learn kicad
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Great, one less thing for me to take on. So you have the gerber/drill data? Mind sharing it with me? Not that I want to start selling them, just to look at. I have a design folder for this project, it’s been a while, do not think I have the fab files.
Hello friends
At first, schematics and many photos of the boards were posted, so I designed my own boards in Kicad.
Although I haven't gotten around to completing the project (maybe someday I will).
To summarize, I have the files for the preamp, the phono stage, and the adjustable power supply, I think they're the latest versions.
If there are no problems and the forum rules aren't violated, I wouldn't mind posting them, considering I don't know if there are any errors since I haven't followed them.
Regards
At first, schematics and many photos of the boards were posted, so I designed my own boards in Kicad.
Although I haven't gotten around to completing the project (maybe someday I will).
To summarize, I have the files for the preamp, the phono stage, and the adjustable power supply, I think they're the latest versions.
If there are no problems and the forum rules aren't violated, I wouldn't mind posting them, considering I don't know if there are any errors since I haven't followed them.
Regards