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-   -   The Kuartlotron - keantoken's simple error-correction superbuffer (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer.html)

carlmart 17th October 2016 09:18 PM

Yes, of course.

ammel68 18th October 2016 05:20 PM

Quote:

Originally Posted by keantoken (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post4859445.html#post4859445)
The 2.7R sets the bias current, so the chipreg is really a CCS.

Can someone please tell me what wattage the 2.7 and 3.3 ohm resistors need to be?

Thanks.

keantoken 18th October 2016 05:27 PM

The LM317 keeps 1.25V across R1, which means about 0.6V across R3, which sets the bias current at 200mA or so. 1/4W is enough for both resistors I think.

ammel68 19th October 2016 06:15 AM

Thank you keantoken.

BRN 24th October 2016 09:56 PM

Finally put together my my Kuartlotron buffer. I fired it up and the LED came on and there was no smoke. I ran through the adjustments with no problem. I built the buff in an ebay aluminum chassis that has internal measurements of W 9-5/8" x H 2-1/8" x D 6-7/8" with three inputs.

eBay link:Silver 2606A Full aluminum preamp chassis Power amp box /DIY case | eBay

I'm using RJM Audio's X-reg with the recommended toroidal power transformer to power the buffer in the same chassis.

When I turn my stereo on I get humming through both speakers. It is not real loud, but can be heard from the listening position. The strangest thing is when I turn the buffer off and leave the Folsom TDA7297 amp powered on I get a loud hum and on the second input I'm picking up a radio station.

I'm pretty sure that the transformer is the culprit, but not sure what I want to try in order to fix the problem. I can get some MuMetal to isolate the power supply or I can move the power supply into a different chassis. If I move anything into a different chassis it would most likely be the transformer and regulators. I would leave the X-reg with the Kuartlotron buffer.

If anyone has any other suggestions or thought on this problem I'm open to ideas to fix the problem.

Thanks,
Brad

BRN 25th October 2016 03:21 AM

1 Attachment(s)
This is a picture of the build.

Destroyer OS 25th October 2016 04:11 AM

It looks like the Volume device is running near the power switch? For AC?

When the buffer is off, parasitic qualities dominate. They don't really tell anything about the actual buffer itself.

keantoken 25th October 2016 04:22 AM

Try measuring the ACV at the inputs and outputs of the buffer to see if the hum is coming from the buffer or if it's something else. If you are using it for phono, then you may need a better PSU and careful chassis construction to keep noise low.

Hum or unusual behavior is no surprise when turned off. There is no muting circuit. EMC problems with your chassis could be contributing to the RFI.

AndrewT 25th October 2016 09:21 AM

Quote:

Originally Posted by BRN (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post4866364.html#post4866364)
Finally put together my my Kuartlotron buffer. I fired it up and the LED came on and there was no smoke. I ran through the adjustments with no problem. I built the buff in an ebay aluminum chassis that has internal measurements of W 9-5/8" x H 2-1/8" x D 6-7/8" with three inputs.

eBay link:Silver 2606A Full aluminum preamp chassis Power amp box /DIY case | eBay

I'm using RJM Audio's X-reg with the recommended toroidal power transformer to power the buffer in the same chassis.

When I turn my stereo on I get humming through both speakers. It is not real loud, but can be heard from the listening position. The strangest thing is when I turn the buffer off and leave the Folsom TDA7297 amp powered on I get a loud hum and on the second input I'm picking up a radio station.

I'm pretty sure that the transformer is the culprit, but not sure what I want to try in order to fix the problem. I can get some MuMetal to isolate the power supply or I can move the power supply into a different chassis. If I move anything into a different chassis it would most likely be the transformer and regulators. I would leave the X-reg with the Kuartlotron buffer.

If anyone has any other suggestions or thought on this problem I'm open to ideas to fix the problem.

Thanks,
Brad

Quote:

Originally Posted by BRN (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post4866558.html#post4866558)
This is a picture of the build.

quite a lot of twisted pairs used to reduce loop areas.
The hum must be due to a wiring error.
Disconnect one channel completely and sort the working channel.
Then disconnect that corrected channel and sort the other channel.
Once you have both channels wired correctly you then need to test again with interconnects attached to both inputs.

carlmart 25th October 2016 11:42 AM

Quote:

Originally Posted by Project16 (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post4850889.html#post4850889)
Being very satisfied with my Kuartlotron with Sulzer regulator type I was wondering if the regulator Nazar would be an excellent choice by incorporating it directly on the PCB.

I haven't read all the pages, so probably this question is already answered. Is it possible to eliminate L1?

L1 is part of a noise filter, right? Even if for an LC it should be before the cap.

Using a regulator (series, shunt) or cap multiplier wouldn't filter noise and allow deleting L1?

A Sulzer reg would probably be the almost ultimate regulator for this application, so what would a Nazar regulator improve over Sulzer's?

When you say incorporate on the pcb, you mean all the two Nazar's regulators?


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