Pioneer RT-707 Recap + Head Relap

xlbee

PIONEERFREQ
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It's very exciting!!! I received my relapped heads back from JRF Magnetics last night and put my freshly recapped RT-707 back together. I did a preliminary test and everything works great so far. Haven't tested all functions yet. I need to test all functions, do the electrical adjustments and then I'll post my recap list and notes.

Stay tuned boys and girls!

Edit: the notes and recap list are in post 8.
 
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All functions tested and everything is working perfectly. The relapping and optical alignment of the heads performed by JRF is great, both channels loud and clear with good bass response and crisp highs. I still need to do the electrical adjustments but so far, so good!
 
It's a great feeling isn't it? I remember the excitement i had when my 909 headblock came back from JRF. How much headlife do you still have?
 
It's a great feeling isn't it? I remember the excitement i had when my 909 headblock came back from JRF. How much headlife do you still have?

I sent in head blocks for two RT-707s and one four track head block for an RT-2044. They are all between 50 and 90%. The best set is all above 70%.

The electrical adjustments for the recapped RT-707 are done. I gave it a listen and it sounds fantastic. My rare copy of Midnight Blue by Kenny Burrell never sounded so good.

Gonna be a busy weekend but I'll get some notes up here soon along with my recap list.
 
All in all, the RT-707 recap isn’t that bad. Everything is relatively accessible. If you’re just doing a recap that is… If you’re going to get the heads relapped there is some additional expense. If you are going to do the mechanical and electrical adjustments as well, that’s where it gets tricky. This also means additional expense for a calibration tape. I went for the whole nine yards and the results are awesome. I also changed the direction indicators to LEDs while I had everything open.

If you decide to recap yours and you use my recap list as a reference, pay attention to the comments column. That’s where I list any anomalies that I find along the way. Here’s some notes about a few of these:

The Meter Amplifier Assembly (RWX-155) is missing from my unit due to a rev/production change at some point and the only service manual and schematics I could find include this board. Some of the parts from this board were moved onto the Playback Amplifier Assembly.

Compared to the parts layout I have, there’s a cap missing from my Power and Oscillation Assembly. No holes, no markings, it’s just not there.

There are a couple of caps that are a different value on the Head Amplifier Assembly than what the parts layout shows. In cases like this I always replace like for like with what I find on the board if they look factory installed.

One quick note about the three large caps mounted to the chassis: they are not electrolytic so I did not change them in my unit.

Standard disclaimer: The attached parts list represents a snapshot in time. It's the right list for my unit, yours may be slightly different. Mouser part numbers change and they run out of stock so you may need to make some substitutions. The list should also be inspected by one of the AK gurus (you know who you are) to ensure it meets with their approval. The mods are more than welcome to publish it in the AK recap database if approved by one of the AK gurus.
 

Attachments

  • RT-707 Recap List.pdf
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I got my heads back from JRF also and pinch roller form Terry . All installed and so far so good . I have a MRL cal tape but I'm not sure it has Wow and flutter freqs. on it. Rookie here so I'll be watching this thread.
 
Calman, I don't see that adjustment in my manual. Did I miss it?

I wasn't really planning on adding more to this thread. I recapped, didn't do the mechanical adjustments because the deck didn't seem to need it, didn't adjust the heads because JRF did the optical alignment, did the electrical adjustments as per the service manual and it sounds great to me. Possibly a tiny bit bright so I may back off on the EQ adjustment a bit.

If you have questions, I'll try to help but I'm certainly no expert. This is the first reel to reel alignment I've done.
 
Its 9.6 tape speed adjustment using STD tape 101 . Do you what frequency that tape is? I haven't done any adjustments yet .I would like just to check them all first and see how close they are . This my second deck I worked on. I don't have a tension gauge so I'm going to try a pull meter for electric hobby trains. It reads kg, oz, LBS I'll have to do the math . JRF does good work my heads look new ,FP 60%, RP 70%, R 70%
 
Great question!

The test tape I have is recorded at 19 cm/s (7 1/2 in/s), assuming yours is too. So if you are looking for the frequency counter to read 3000 Hz at 19 cm/s then the frequency on the tape must be 3000 Hz. For 9.5 cm/s (3.75 in/s) they are calling for a reading of 1500 Hz because that same tape with the same test signal is travelling at half the speed of the previous test so what is recorded on the tape is 3000 Hz.

Make sense?

The instructions really are somewhat lacking. You also have to assume that the frequency counter is connected to the tape out as the manual doesn't actually say.
 
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yes it does make sense , thanks. My little pull meter works measurements were close enough for me . I couldn't do the pinch roller one. Electrically tests next . Did you oil your motors ?
 
No, it looked like someone had oiled them recently and too much can definitely be a bad thing. Are you going to do steps 11.4, 11.5 and 11.6? Do you have a plastic adjustment tool for the coils?
 
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No. I 'm not touching those as long as they work . I'll just check 11.1-11.3 ,adjust if needed.
 
I ran my MRL cal tape and all was close until I went to set the VU meter's 0 db . My left side is a little weaker L= 387mv AC, R= 450mv AC . The levels will balance out in the + db area . I cleaned switches and pots, incoming signal is balanced . any ideas ? Cold solder joint maybe
 
Its not the meter the signal is weaker. I can adjust VR109 but that wouldn't change the actual signal strength
 
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