sony rc-651 reel to reel

8/4/2009 10:20:54 PMbill

alrighty, another request for help. i have this tc-651 reel to reel. mechanically, it works great, but playback/record, well, not so well. heads have average wear, but still have life. i have run this through demag and not much difference in sound. this unit appears to be one of sony's better units, but since i only paid 5 bucks for it, i wonder if it's worth refurbing. i want to because r2r's just don't appear to be found much anymore, in decent shape.

can someone that has sam's photofact look and see if there is schematics/service info and let me know what volume these are in, or if you want, email them to me and i be more than happy to donate a few dollars to your pocket for expenses or even to this site.

i'd like to restore this unit.

thanks!

bill

8/4/2009 10:51:01 PMEdd

SIR Bill . . . .

You certainly got your moneys worth with that item. The unit is from the early 70’s . . .and, naturally, using solid state circuitry.

Most common failure items associative with the capstan, supply and take up reel motors were their associative series run capacitors C801, C802 and C805 respectively. I have tech info but is massive and pertinent to all of the different board assemblies, which you soon will be finding on initial disassembly for inspection.

First things first:

Which would be the power supply, with its two 22 VDC supplies being derived from series pass transistors Q3 and Q802.

Let me know what you initially find inoperative on the unit.

73's de Edd

8/4/2009 11:28:01 PMbill

hey edd,

so far, everything mechanically works. ff/rr/auto reverse. i did have to put new brake pads on, (using a lone left hand leather gardening glove). it plays, the sound is good, and this is from a known good tape. i have also recorded to tape, and that sounds good, but both, don't sound as good as i think it could. seems a little more bassy than i like, but i think that it's the tape.

biggest issue i have with it at the moment is that the tape playback is not working while recording. neither channel, when selected will play what has been recorded. i know that it did work as i did test it when i first got it. saturday night, i did hook this unit up to my stereo, a pioneer sx-1010 by the way... :), and let it run for a few hours playing a tape that had big band on it and it sounded good for the duration of the time i had it on. i guess after that is when the "tape" playback while recording decided to go on it.

i'd check those caps you listed, but i don't have any documentation for this unit whatsoever. i'd be happy to do as i stated and donate $$ to you or the site if you would like, if you send what you have. send an email to the email addy for the post and i'll reply with the email addy that i use that has a larger attachment limit if you choose.

thanks edd!

8/4/2009 11:07:41 PMWarren

If it sounds " muddy " it may need a new head. If you have a know good prerecorded tape, see if that sounds any better. A worn head recording, played back on the same worn head, sounds about twice as bad.

8/4/2009 11:53:00 PMBill VA

:If it sounds " muddy " it may need a new head. If you have a know good prerecorded tape, see if that sounds any better. A worn head recording, played back on the same worn head, sounds about twice as bad.
:
Bill

8/5/2009 6:45:11 PMMike C.

Hi Bill,No luck on the service info for your recorder.One out of two ain't bad,though.Later.

8/5/2009 9:07:25 PMEdd

SIR Bill . . . .

O.K., and with having only minimal initial supplied info, it looks like we can mark off the power supply, by that operative info that you have just given us.

On cleaning the heads, I additionally go a step further in removing any slightest remaining trace of imbedded oxide by using the rolled up paper portion of Q-tip after using the cotton swab initially and then breaking it off to expose a fresh portion of its rolled up paper “stick” . Then soak it in in denatured alcohol and clean away with its end until no red or black residue comes forth on the white tip.

On small cassette units, since they are much smaller, I might additionally use a soaked round wooden toothpick.

Most importantly, have a HIGH intensity light flooding right upon the work area.

As per the tech info. . .stand waaaaay back and prepare to receive pages 65-106 of all of the Sony, schematics-electromechanics info on that unit. . .it may take ‘til Labor day or I might need to break it down more. . .we will try for the whole file initially.

73's de Edd

8/5/2009 11:35:06 PMbill

thanks for the info edd. i will send you an email in the mean time.