signal-dude

do you have schematics on using LM317 power supply to 2270 tone board? I will like to try to build due to your post about making receiver sound better.

Damn, guess its been a while since I've actually logged into AK!

I had measure the channel separation using an HP3562 spectrum analyzer with both frequency sweeps and white noise.

The low channel separation was from a multi-pole rotary switch that I was using for an input selector. I changed to using two switches - one for left channel and one for right. The next improvement came from increasing the separation between the left and right input connectors.

Rob

Re I have replaced all the carbons in the pre-amp section of a Marantz 2270 receiver with Yageo 1% MF's from Digikey.

I also have a 2270, and would love to do this. Any chance that you have the BOM from digi-key...and could I have a copy?

S.Dude,

Hey, I just saw your old post about channel separation. I recently completed a home-made preamp (combo of a B1 for mid/tweeters, and basic non-inverting OPA627 at 6dB gain for my woofers). Cross talk is unacceptable, 2Vpp input random noise = -40 dB at 20kHz. Preamp laid out in two separate channels, all internal wiring shielded. Only thing I can think of is the tiny input selector and maybe the stereo pot.

What did you discover on your build to increase the separation?

Thanks!!

Mark - I received the Black Gate caps. Many, many thanks! Franco

Hi signal-dude, thanks for replying to my post. If your offer is still valid regarding your black gate caps, I'll take whatever you are willing to part with. Let me know what postage costs and I'll send you the funds via PayPal if this is OK. Many thanks, 'Transformer' .... Franco Morante, 391 Payneham Road, Marden, South Australia 5070, AUSTRALIA. Many thanks.