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Sansui 1000A Distortion From Reel To Reel Signal

blistabusta

blistabusta

New Member
I would not say that I have tons of experience with the Sansui 1000A receiver but I have recapped and tuned three of them over the last couple of years. I really have a thing for this model. All three of the 1000A units that I have rebuilt share a particular problem that I cannot figure out and I hope that someone can shed a light on it. Every source component that I use for input (turntable, cassette deck, digital) sounds very clear and three dimensional but when an open reel recorder is used for input into a 1000A, I get a distorted program. I have used various brands and models of recorder for input and the distortion seems the same no matter which deck I use. I have also tried each AUX pair and the TAPE IN pair on the rear panel and I still have this distortion. Is there a fix for this?

Thank you in advance for any advice that any of you may offer.
 
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The 1000A specs this for input:

Input sensitivity: 1.8mV (mic), 1.5mV (MM), 110mV (line)


And for example a Revox G36 delivers:

Output: 0.7V (line)


This may have something to do with it.
 
Thank you for your response. I have calibrated the preamplifiers on all of my tape decks where 3 o'clock on the front panel output control produces 0.744mV. Even with the output control set to 8 o'clock I get this distortion through the Sansui. Could I have an impedance mismatch between my recorders and the 1000A? I do not have distortion while using any of these decks with my Pilot 602, Martel FAX-150C, or Fisher X-100B.
 
Zekman has your answer, the Sansui has a line input of 110 millivolts, and you are trying to feed in a signal of 744 millivolts from the RR tape machine.

All the RR tape machines I have ever used have a real "hot" output and I usually have the output level way down from the "marked" output.

Try putting the RR output control all the way off, put the Sansui volume to a "normal" setting, then bring up the RR slowly to see if you get better results.

Note that all "line" and "tape" monitor inputs go to the top of the volume control (no amplification) but the phono, mic and tape head inputs are amplified by the phono section and the FM comes from a tube in the tuner section.

Hope this helps.

Mark T. :music:
 
The real problem is the difference between pro audio line level, and Hi Fi line level. The tape decks are putting out a pro audio line level (called 0 db) and most hi fi gear from the 60's especially, expect a line level of -10 db. If you want to maintain the best signal to noise ratio, then you need to insert a 10 db pad in line, or just turn down the output, like Mark and Zeke explain, above.
 
My 1000A exhibits the same thing when I connect any of my AKAI's or the TEAC's thru the Tape deck preamps. If your R2R is an Early TEAC 4010,and ONLY on the EARLY 4010's that were put together from a A4000S tape deck and a RA40S amplifier, the wiring is such that there will be 2 RCA cables on the back going to the pre-amp underneath. (The later models changed and these output's are now part of the umbilical).. 2 of these are marked Playback output, . You can disconnect the PLAYBACK OUT(L&R) from the tape deck preamp and run the Playback OUTPUT's on the TAPE DECK (not the preamp) directly to the TAPE HEAD jacks on the 1000A. Then on the Tapedeck preamp are Line IN . Connect these to the RCDR OUT on the receiver/amp. The umbilicals are used as normal. You'll be able to record but lose monitor ability from the tape deck (it works like a 2 head unit now.. I don't use the 1000A for recording so my early 4010 gets the nod here and I can use the TAPE HEAD connection as it was designed to be used. See below for difference.

Otherwise, with the Deck and the preamp connected Normally, connect it to the Tape Monitor from the Line out, and connect line in on tape preamp to amp RCDR OUT. But keep the levels on the R2R VERY VERY LOW, almost to ZERO!!!

The other alternative is to get an L-pad (1 per channel) and adjust so you can use the preamp normally or almost so adn the receiver/amp normally.

Scenario 1 (ONLY IF your Tape Deck is separate from it's PREAMP. EXAMPLE USED is TEAC A4000S with a RA-40S Amplifier combined to become a A4010.) Output is to AUX in the pic but use TAPE HEAD as there is no amplification and no EQ, which Tape Head postion provides.
ScreenHunter_327 Jun. 28 23.33.jpg

SCENARIO 2; Note that the RA-40S Amplifier is included in the setup now. And the playback out is NOW RUN in to the AUX as the EQ is handled by the RA40S amplifier. You must keep RA-40 LEVELS down to almost ZERO to compensate for imbalance. This hook up is indicative of most tape decks/recorders out there.
ScreenHunter_328 Jun. 28 23.35.jpg
If you get L-PADS they go in between the OUTPUT's from the RA-40S to the Tape Monitor on the Stereo Receiver/Stereo Amp .
 
Strange-any reel to reel I've hooked to my 1000A works perfect.I run an Akai GX-260D reel to reel.
 
All of your responses are much appreciated. I will try the L-PAD route. I have tried all of the remedies listed above except the addition of an external attenuator without result.

Thank you.
 
That was some considerable effort to work up that reply Larry, excellent support and spot on as usual. :thumbsup:
 
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