Recent content by nanchangbob

To make sure there is no confusion! 1. Op-amp is in placed and not pulled. 2. Measure pin 7 to ground that is R205 according to the schematic you provided. 3. Measure pin 3 to ground that is R201. 4. Put one tip of your dvm tip on the RCA input center pin and put the other dvm prob tip on...

What is the resistance reading to ground from R201 and R205? What is the resistance reading from both sides of the input capacitor to pin 5 of the op-amp?

OK, I think you need to reset and look at the more analytically. If your going to start messing with electronics you should really do some reading or take a course as it can hurt or even kill you. That said, look at what you have, one channel not operational. If you have one channel working...

Using a test tone and oscilloscope would of course be nice, but since you probably don't have an o-scope you can select AC on your DVM and place the ground lead on the ground pin " of the 6.35 headphone jack. Play a test tone and then place the red lead on left and then the right channel pins...

I replaced the 317/337 supply with MLytic's and quality parts to the Salas BIB Shunt regulated low voltage supply. They are a bit large and pricey to populate.   A couple of other options are the Diyaudio stores super regulator or if you are comfortable with soldering SMD, the power supply...

Well I finally had a day off and finished my experiment with the Salas power supplies.  I tried it on the original board and had just a bit of noise.  I didn't want to deal with it so I finished the new board and swapped some of the parts over.   I've been listening for almost six hours and I...

I learned something today.  I picked-up a 0-15, 0-15 transformer and replaced thee 15-0-15 and the problem has been corrected. The two sides are truly separate. On the 15-0-15 it had three wires.   Now I need to leave for two straight weeks of work.  I will try to  replace the power supply on...

I built the new pcb and tested it and it has the same issue of over current.  I believe when the PS grounds are tied together on the PCB it causes a direct short on the transformer. The transformer was shaking a bit. I will buy a couple of cheap 15v transformers and I believe all will be fine. ...

I received the new PCB and started populating already.  I need to go tomorrow and pick-up a few things.  The new board is a bit smaller but seems fine other than that. It cost about six dollars shipped. I have damaged builds by doing mods in the past and given myself extra work.  I will play it...

I removed the large power supply caps C7 and C8 the two regulators and R9 and R10 I put the + and - voltages on the corresponding pins on the empty regulator pins and then put the grounds on the grounds.  Did I miss something?  I wanted to try it after pulling all the power supply parts but...

Sorry about taking so long to get back.  I ran into an issue.  I can use my shunt PS on either the positive or negative but not both at the same time.  Let me explain!  When I hook up the positive or negative alone it works fine on that channel but if I hook both up at the same time it blows a...

I wrote sometime ago about wanting to try to improve the performance of the BCL clone by improving on the power supply.  I've have done a lot of upgrades on my current unit and it really does sound great.  I changed the original input caps from Wima MP-10 to some Mundorf Zn pulls I bought and it...

Actually mine sounds very good right now and I listen to it more than my other amps.  I've just built some amps and preamp's and found the more I lowered the noise floor the more information came through and I wanted to push this one farther and see what it does.   The 317 and 337 are not bad...

I think you will have difficulties finding genuine Philips transistors.  Most of the one you see on Ebay are fakes from China.  I know first had because I'm living here and see them all the time.   I changed capacitors from Wima Mkp 10 to Mundorf ZN capacitors I got on a bargain basement...

Hi Patrick,   I like the thought of using an alternative  to the 317 and 337 regulators.  I think the LT1083 is a positive regulator?  Wouldn't you need one side to be a LT3015?    I will be heading to the U.S. next month to visit family and I have a set of Salas BIB low voltage shunt...