I'm In, Part 8. ReVox A700, Beans Spilled Everywhere...

[Dre_J]

I'm In, Part 8. ReVox A700, Beans Spilled Everywhere...

Yeah, I'm 100% sure my Ki's disease is no longer in remission!

Last week, I added a ReVox A700 to my collection.

The deck came with two complete 1/4" tape headblocks for 1/4-track (4-track) and 1/2-track (2-track) along with a remote control and variable speed control.

Interestingly, this deck has a cast frame and transport similar to the Studer B67 and features constant tension for tape handling.

The Deck had some issues that I've ironed out but still more things necessary to be done.

However, she's starting to purr...

Images are shown below.

ReVox A700 with Two Headblocks, Remote Control, and Variable Speed Control:


Revox A700 Playing 15IPS 10.5" Reel after repairs and adjustments:


Dre

[Dre_J]

Here are a couple videos of the ReVox A700 playing 10.5" reels at 15IPS:

• ReVox A700 - up close playing tape at 15ips after a few repairs playing a few seconds of Bad Company

Direct link:ReVox A700 - playing tape at 15ips - YouTube
Embedded link:

• ReVox A700 - 15IPS after repairs and CCIR EQ added playing Peter, Paul, and Mary

Direct link: ReVox A700 - 15IPS after repairs and CCIR EQ added - YouTube
Embedded link:

Dre

[rbbert]

Nice!

[ack]

Very nice!

[Dre_J]

This post is a follow-up on some of the work required to get the ReVox A700 back to being fully functional.

A few notes on the ReVox A700 both before the functioning videos and repairs/adjustments after are mentioned below:

- During initial testing of the deck for full functionality, it let out some magic smoke about halfway into the first tape played to assess functionality. One of the suppressor capacitors (RIFA) in the power supply circuit bit the dust and took out a fuse in the process. The issue was repaired with replacement suppressor capacitors I had on hand. I also replaced other RIFAs that were immediately at risk. (the remaining ones will be replaced when more parts arrive.

- Intermittent distortion in both channels (solved)

- Tape counter belt melted and needs replacement (fixed but temporary belt used until replacement ordered)

- End-of-Tape sensor lamp blown (repaired with replacement part)

- Supply reel rewind issue (repaired)

- Wow and Flutter issue at end of tape (repaired)

- Pinch roller tension/pressure needed adjustment (repaired)

-Audio output levels adjusted

-Source voltages (+/- 12VDC and +5VDC) adjusted to proper levels for internal circuitry

- End-of-Tape sensor sensitivity adjusted

- Capstan motor servo PLL sync reset and adjusted

- Custom adjusted the 15ips NAB EQ and changed it to 15ips CCIR/IEC for 1/2-track (2-track) 15IPS tape playback while leaving the 7.5IPS and 3.75IPS set for NAB in order to play 1/4-track (4-track) commercial tapes when swapping to 1/4-track (4-track) tape headblock.

- Reset and adjusted the Tape tensioning arms for take-up and supply sides.

- Tape tension arm dampers were disassembled, cleaned out, and repacked with new damping fluid.
Note: photos of steps to do this are posted at this link here: ReVox A700 Tape Tension Damper Repair and Repacking - Audionirvana.org

- Tape tension rollers disassembled, cleaned, and reinstalled

That's the list of most, but not all, things done to date.

The ReVox A700 tape deck is kitten purring now. There are a few maintenance items to get to --mainly replacement maintenance parts on order-- later on. When the parts arrive, I'll do the final bit of component replacement preventive maintenance.

ReVox A700 Spooling Tape:


Dre

[ack]

Andre I need to send in my B77 for repair and upgrades. I don’t care for factory spec parts, looking for real upgrades. Can you recommend someone ?

[Dre_J]

Andre I need to send in my B77 for repair and upgrades. I don’t care for factory spec parts, looking for real upgrades. Can you recommend someone ?

I'd suggest a separation of the two issues. Repair is one thing and an upgrade of some sort would be another.

For a repair, there are a few (including Tapetech or Soren) who can work on and repair the deck.

I'd probably need to know what it is you want to upgrade. If it's the playback chain, you can talk to Tapetech about his external repro. If it is for something else non-standard that you have in mind, you may need to do a little searching for someone willing to do what it is you are wanting done.

I'd want to know more before making suggestions or pointing you to someone to help you beyond what I've mentioned.

Dre

[ack]

I'd suggest a separation of the two issues. Repair is one thing and an upgrade of some sort would be another.

For a repair, there are a few (including Tapetech or Soren) who can work on and repair the deck.

I'd probably need to know what it is you want to upgrade. If it's the playback chain, you can talk to Tapetech about his external repro. If it is for something else non-standard that you have in mind, you may need to do a little searching for someone willing to do what it is you are wanting done.

I'd want to know more before making suggestions or pointing you to someone to help you beyond what I've mentioned.

Dre

Thanks. For starters, all caps must be replaced, it's been a while - all parts are original. And we go from there; nothing drastic. The only issue right now is that the left channel IN is down 10dB which I know is a contact issue. Somebody should be able to perform a little magic by using newer, better parts.

[Dre_J]

Thanks. For starters, all caps must be replaced, it's been a while - all parts are original. And we go from there; nothing drastic. The only issue right now is that the left channel IN is down 10dB which I know is a contact issue. Somebody should be able to perform a little magic by using newer, better parts.

Ok.

For the recap and repair, both Tapetech and Soren can do the work. I'm sure there are others, too. There is a labor charge for a full recap that adds up quickly. However, considering what one would pay for some of our hobby's accessories, it may not be too bad: especially when thinking of wanting a vintage piece like that to have a second life.

Dre