Sam Burden
Active Member
Thanks Bob
Technical help with a Pioneer RT- 707 Please
- Thread starter Sam Burden
- Start date
Thanks Bob
buffdriver
Active Member
The Mic Amplifier Board (RWF-065A) has 6 x 2SC1344 transistors (Q201/201, Q205-208). The Playback Amplifier Board (RWF-069) has 2 x 2SC1344 transistors (Q107/108). I changed these transistors and lowered noise level significantly in those circuits.
Sam Burden
Active Member
Thank you buffdriver, I looked through the service manual and also found 2 of those transistors on the power oscillator board so I ordered 10 NTE199 (NTE199 - NPN Transistor, SI-Low-Noise)
and am going to change them all out.
sawdust
Solid walnut covers all my gear
check out this thread post # 33 http://audiokarma.org/forums/index....7-capacitor-upgrade-and-service.790700/page-2
it helped me when I recapped mine
it helped me when I recapped mine
buffdriver
Active Member
Recommended replacement for the 2SC1344 is KSC1845FTA. I also changed out the 2SA672 with KSA992FTA. Best of luck! Let us know if this solves your issue, and BE CAREFUL for the pin outs when replacing the transistors.
Sam Burden
Active Member
Thanks for the reply. I am wondering if anyone has tried the NTE199s, I had done some research and they seem to be designed for low noise. I already ordered them. Dont have a problem ordering the KSC1845s but am curious as to anyones opinions on the ntes. They were about 5 times more expensive than the KSCs and hate to just put them away. However I can do that. See what you think from the attached spec sheets and maybe you can tell me what your thoughts are between the two. I am not trying to reinvent the wheel here but would like an opinion. Thanks Sam Edit, I went ahead and ordered the suggested transistors but would still like an opinion on the NTEs.
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Sam Burden
Active Member
Saw somewhere else where the NTEs were not a good fit in this unit. Not exactly sure as they are speced as a direct replacement on cross reference lists as well as being designed for low noise in audio amplifier situations where the ksc1845s say they are good usage in medical equipment. I am not an expert on transistors so I will defer to the general consensus and use the KSCs but it sure would be nice to find someone who has used them so that there was an actual real world comparison as to which measured out with the best noise reduction. I guess if I not happy with the reduction I will swap them out and see.
Sam Burden
Active Member
Thank you for the link. I had done a search but for some reason did not come on this thread. I am going to use the recommended Nichicon for the control and switch boards but am going to use Elna Silmic ii s in the audio portion of the deck. I have used these in Marantz amplifiers and am very impressed with the sound quality. Figure if they work great in my Marantz 1060 and 2325 then they will also work great in the Pioneer.
Sam Burden
Active Member
Thanks Buffdriver I have the the recommended transistors on the way.
Sam Burden
Active Member
Also in answer to my earlier question as to whether the small holes in the back of the reel motors are oil holes. Yes they are after looking closely with a light you can see the felts behind them for absorbing the oil. Also finally found one post that said that depending on the vintage of the RT-707s they could have oil holes. Evidently some of them didnt.
Sam Burden
Active Member
Sorry Mark, I had seen that those caps could potentially fail and that they were powercaps so I didnt take the time to review the schematic and had I, I would have realized that there are four motor caps in this unit. The two reel motor caps and these two which I believe are the capstan motor caps. So I am going to leave them alone also and deal with it down the road if I have a problem. Sorry for my confusion next time I look at something I will review the schematic to see what there function is rather than rely on someone elses statement.
sawdust
Solid walnut covers all my gear
I used Nichicon UPW in place of the CEA caps and Nichicon UKL in place of the CEANL caps they are recommended by Mark the fixer I have used them in all of my restorations, I only replaced 6 Transistors in mine on the RFW-065-A, sense the restoration the play and record quality is flawless , this was the last piece in my system that was still original I wasn't going to restore it I'm more into cassette tapes all my vinyl is on them, I have been doing a lot recording on the 707 sense the restore with no issues, I glad I restored it now it was worth the time and effort and research I did . thanks to all the AK members that contribute their time to make these projects possible.
Amos
Sam Burden
Active Member
Well it turns out that the clicking which sounds like a machine gun is not a component issue but a pairing problem with my amp. I just got a Tandberg 64X up and running and it has the same issue going into my Marantz 1060 so I put them into a Yamaha AV reciever that I have and same issue. So am not sure what I need to do to remedy the situation. Although I have wanted reel to reel since I was a kid these are the first ones I have ever used so am unfamilar with the issue. I have tried tape monitor ins, tape ins and aux ins and makes no difference but I dont have the issue with other formats. Cd etc. I did start a new thread on pairing the decks to amps in case no one sees this post. As far as the RT-707 is concerned it does have white noise which I am pretty sure is the noisy transistors on the mic board. I have the new transistors on hand that were suggested earlier but have decided to go ahead and do a full recap of my unit since I have already done the servo, power, and switching boards. So as soon as my Mouser order gets here with my caps I will change out the caps and transistors at the same time and continue on. Thanks to everyone who has helped me as well as given me links to other posts. I am using the recommended caps with the exception of the Nichicon FGs I am using Elna Silmic ii s instead. I have used these in Marantz amps and the sound from these caps is fantastic.
Sam Burden
Active Member
Thank you for the post. My cable modem/ wifi router is indeed the problem. Once I unplugged it the problem is gone. Now I need to figure out where to move it to. Sam
