99 Problems.... The Revox kind.

[Hxt1]

Hi again CLEM! I'm now delving into the Pr99... the service binder sure helps! Especially now that I know how to read it!
So I'm off to 'Lee's Electronics" to purchase more parts.. then, on with the show!
Without You and Charlie, I'd have washed my hands of the thing completely... a shame for sure!
looks like I'm getting a B77 on Friday, A fellow who runs a radio station on the sunshine coast is selling me some new Zonal tape, and throwing in the B77... I used to wonder how guys end up with 10-20-100 reel to reel machines! Seems these things just find their way into one's home!! The G36 is gone, I tell you, the dubs I made with that machine sure do sound fantastic!
Ok, I hope to have this baby up and kicking out tunes by next week this time!

 

[bblue]

Re: PR99's, I have several of them and have done several experiments with the audio on them. All of their line output stages significantly degrade the sound, even though offering the advantage of 600 ohm balanced outputs. I found the best results (by far) was to clean up the tape reproduce boards with new caps, some additional bypasses across the supply rails, and general cleaning. Then use the Monitor Jack outputs (a din connector at the top) to drive your playback/dubbing gear. At that point you're at the output of the tape head reproduce boards and bypass all the output processing. It's really a significant improvement.

Also be sure and calibrate the head reproduce amp to an alignment tape for high output tape. This stage has precious little headroom for extremely hot tapes, and will easily flat top (clip peaks) long before you actually notice it (it sounds more like tube gear headroom limits).

You'll note in the manual that there are different gain (feedback) resistors depending on the heads used, as mono heads have higher output and need less gain, 1/2 track heads have higher output than 1/4 track, etc. I ended up using the gain resistor values for the mono heads, just to allow sufficient headroom for high output 2 track tapes.

--Bill

 

[Curt Palme]

I've worked on lots of Revoxes, mainly A and B77s, and am local to you (Langley). I can look at it for you if you wish. Please contact me through my website at www.curtpalme.com.

Cheers!

 

[amirm]

Welcome to the forum Curt .

 

[Curt Palme]

Thanks Amir! Found this forum googling for something else, and now I know where most of the avs people went.

I won't be spending a pile of time here, as my focus is back on doing commercial sound system installations. I love RTRs, have a couple of Technics 1500 and a Crown and a couple of Akais here, but alas, no time, and pretty much all of my tapes need baking. Plus, I listen to most of my music on road trips, and alas, the 1500s aren't overly roadworthy..

Still, hopefully I can help anyone local with RTR issues if they need service, as I'm pretty well versed with them.

Cheers!

 

[Steve Williams]

Hey Curt

I knew you'd find your way here

Any experience with the pro machines

 

[Hxt1]

Re: PR99's, I have several of them and have done several experiments with the audio on them. All of their line output stages significantly degrade the sound, even though offering the advantage of 600 ohm balanced outputs. I found the best results (by far) was to clean up the tape reproduce boards with new caps, some additional bypasses across the supply rails, and general cleaning. Then use the Monitor Jack outputs (a din connector at the top) to drive your playback/dubbing gear. At that point you're at the output of the tape head reproduce boards and bypass all the output processing. It's really a significant improvement.

Also be sure and calibrate the head reproduce amp to an alignment tape for high output tape. This stage has precious little headroom for extremely hot tapes, and will easily flat top (clip peaks) long before you actually notice it (it sounds more like tube gear headroom limits).

You'll note in the manual that there are different gain (feedback) resistors depending on the heads used, as mono heads have higher output and need less gain, 1/2 track heads have higher output than 1/4 track, etc. I ended up using the gain resistor values for the mono heads, just to allow sufficient headroom for high output 2 track tapes.

--Bill

Cool, that's good to know, the bias tweaks etc.
I've already wired my RCA output jacks from the 'monitor ' output, and tweaked the board. But I didn't know about the different tape formulation eq's and all.
This deck will be playback only, and thanks to some members of this forum, I have a source of great , tapes that will keep me busy for some time to come!
Cheers...

Curt, I'll be contacting you tout suité!

 

[bblue]

Cool, that's good to know, the bias tweaks etc.
I've already wired my RCA output jacks from the 'monitor ' output, and tweaked the board. But I didn't know about the different tape formulation eq's and all.
This deck will be playback only, and thanks to some members of this forum, I have a source of great , tapes that will keep me busy for some time to come!
Cheers...!

Well, if you have a manual look at the comments and parts value for a feedback resistor in that first stage that you adjust for a mono head. Use that value and you won't overload the preamp on really HOT tapes. Then, on the reproduce output control, run it full open, to compensate for the lower gain. Works very well! And you've probably read elsewhere to remove the transistors (fets) that bridge the output to ground for muting. They change the sound slightly by just being there.

--Bill