Upgrading the electronics of my Revox B77 MkII

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
OK we all know about JRF Magnetics for the best in the tape head business... But has anyone ever made replacement record and playback electronics for these decks? Not sure if and how the bottlehead stuff will work with the Revox... Any pointers?

Thanks
 

eugen_syd

Well-Known Member
Jun 20, 2010
44
0
351
Hi Ack,

What exactly you want to do? Which B77 you have, what set up? (speeds and 2 or 4 track?) What equalization you want to have?

Cheers,
Eugen
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
It's a Mk II 4 track, 3-3/4 and 7-1/2 ips. I want to be able to play and record with the IEC curve and abandon NAB, same otherwise configuration. The real goal of this is to replace the aging and outdated electronics at the very least.
 

eugen_syd

Well-Known Member
Jun 20, 2010
44
0
351
Ack,

According with the REVOX SERVICE MANUAL in order to move to IEC you have to move to 7-1/2 and 15ips. To my knowledge that involves changing the motor or the diameter of the shaft. Funny you know I moved all my Revoxes the other way, from fast speed to slow and one from IEC to NAB. Is it IEC that good? I also have a facia available with the fast speeds. Still have a PR99 in the fast speeds. It is very easy, get sevice manuals from ftp://ftp.studer.ch/Public/Products/Revox/ and see the IEC boards. You can upgrade your NAB boards to IEC and viceversa. All REVOX manuals are there.
I had a great experience on my last trip in Germany meeting people from ISR-EV. This is a REVOX club in Germany formed from 5-6 members which as a hobby recondition REVOX and Studer machines. Have a look at http://www.isr-ev.de. I became member of the club too and sent my A700 for full reconditioning. They are using fully enclosed trim pots and replace every component which needs to be replaced. Re-align your machine on their own frame and send the components back. They will tell you which parts you have to send. I packed today a pretty large box and is on the way. Can not wait the results and I will share with everyone on return of the machine the results. I saw a A700 upgraded with parts of B77 and they call it B700. It is plretty clever made with a 2T head also so you can play
2T and record 4T.
I hope this helps and happy to go to more detail if you want to take the IEC path. The advantage is toping up the standard, probablythe best is CCIR. Disadvantage is that you have to play the tape on the same machine and move to 15ips recording (pretty much along the line of THE TAPE PROJECT). You can make it a TAPE PROJECT MACHINE, go and visit the tape project forum and you can electronicaly enhance your motor without fisicaly replacing it (wonder why Willy Studer did not do that....and bothered to build ticker shaft. hehehehe)
Regards,
Eugen
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
Hmm, this doesn't sound right. The speeds can be easily changed with a capacitor replacement, that much is well known and documented on the Tape Project forums and reeltoreel yahoo group. What they also show up there is minor circuit mods to convert to IEC equalization. These changes can be done for $1000, I have confirmed. What I really want, though, is complete overhaul of the electronics plus the mods. But it looks like that link you sent will help, so big THANKS for that.
 

eugen_syd

Well-Known Member
Jun 20, 2010
44
0
351
Hi Ack,

I went and met this guys in Germany. My A700 is now there. I will post my experience when my machine is back together.

Regards,
Eugen
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
Great find! I will contact them about my goals... Since the speed change is pretty simple, I am wondering if they can give me another new switch to select the speed bank on the fly, with a little circuit they will have to come with (no big deal, just two capacitors and a switch)... This sounds very promising, especially if they can upgrade the electronics, which is the most critical thing for me.
 

eugen_syd

Well-Known Member
Jun 20, 2010
44
0
351
John,
there is a little bit more to it. I'll do a full posting on UPDATING reel to reels once my parts arrive from Germany. It is a little bit hard to get in touch with Peter because he is slack responding to his mail but his work is incredible!
Regards,

Eugen
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing