Revox PR99 remote control

Netlist · 16th March 2006, 01:05 PM

A revox PR99 has lost his remote control plug. It's needed when no remocon is used and plugged in the socket, making one or more bridges to make the recorder behave. Without plug, everything works fine except the play button has to be kept pressed. Could someone with knowledge of logic electronics find out what pins I have to bridge to fix this problem.
Schematic here.

/Hugo

Ghianni · 17th March 2006, 11:22 PM

Hi,

I believe that is like Revox A77 dummy connector. Go there http://www.obsoletemedia.com/tapedecks/a77remote.htm perhaps it will help you.

Ghianni.

moamps · 18th March 2006, 08:27 AM

Hi,

the standard wired PR99 doesn't need any connector with setting bridges instead of the real remote controller. Your PR is maybe tweaked. Just check Fader Start Logic Pcb for changes. Check also what's source of +24V signal on the pcb for the start signal.

Regards,
Milan

Netlist · 18th March 2006, 08:56 AM

Ghianni
I found out, as Milan said that no plug is needed in the PR99.
Next thing I looked for was the ‘tape end sensor’ and I believe its working properly. Q10 stops conducting when the sensor light is interrupted. The 24V is 28V however. 5V is present.
There is no indication of tweaks inside.

Looking at the ‘fader start logic’ schematic, I assume K1 is activated when the ‘tape dump' button is pressed. In that condition, the play button stays active. FFW and REW don't work which is a perfectly normal condition.
I forgot to tell in my first post that FFW and REW don't stay put as well.
My lack of knowledge with ports and logic as used in the 'tape drive control' schematic prevents me from fixing that beauty.

/Hugo

moamps · 18th March 2006, 10:26 AM

Hi,
does it going into play mode without the tape present?
Is +24V present all the time at play signal line on the control board?
Can you stop machine from the play mode?

Quote:

Originally posted by Netlist
My lack of knowledge with ports and logic as used in the 'tape drive control' schematic prevents me from fixing that beauty.
/Hugo [/B]

I have few old PRs for spares and can send you the critical boards for free. PM me if you are interested.

Regards,
Milan

Netlist · 18th March 2006, 10:26 AM

Persistence is sometimes a good thing.
A tantalum (again) was short-circuit. For those interested, C2, a 3.3µF cap on the Fader start logic PCB.
Thanks for helping.
Edit: Milan, thanks for the great offer. I'll remember that.

/Hugo

anatech · 18th March 2006, 11:45 PM

Hi Hugo,
Yes, the tantalums. I change them out for electrolytics. The dummy plug comment really threw me Hugo! I always forgot to put the A/B-77 plug back in while working on them. I couldn't recall the PR-99 with those memories rolling around. (ever stick the case back on with the dummy plug still in?)

Also, the bridge rectifiers tend to overheat. I have installed heatsinks on them in the past with thermal epoxy from Wakefield.

The PR-99 was one of my fav machines. Pretty too!

-Chris

Netlist · 29th March 2006, 06:18 PM

Chris,
Didn't notice your post till now.
That PR99 was in real bad condition. Had been standing for years in a moist area. The cost to repair that would be enormous.
The owner is a very caring pro but has no money to store his equipment in a decent garage and even less to pay repairs.
So I fixed what had to be fixed and let the rest alone.
Nice machine indeed.

/Hugo

anatech · 30th March 2006, 12:12 AM

Hi Hugo,
What other choice do you have then? I do the same in those situations, or condem the machine. I must admit I'm not nearly as interested in proving I can make junk work anymore!

-Chris

chanwoo · 24th May 2009, 02:50 PM

Gentlemen,

A year ago, I bought used PR99 and I found something strange as below. I believe someone can explain what happens.

1. When I turn on power SW, it plays automatically regardress tape present. Is this normal?

2. 'PAUSE' butten only working when I holding it down while playing music. And playing again when I release it. Is this normal?

3. I could hear hum from monitoring speaker and it actually amplifying by turning volume when playing PR99 without tape set and I pretty sure it still humming when playing music but can't recongnize because of music. Strangely it's not appear from main speaker. Is someone have an experience about this?

Please give me any of your idea or cure.

Thank you in advance.

16th March 2006, 01:05 PM	#1
Netlist diyAudio Moderator Join Date: Jan 2003	Revox PR99 remote control A revox PR99 has lost his remote control plug. It's needed when no remocon is used and plugged in the socket, making one or more bridges to make the recorder behave. Without plug, everything works fine except the play button has to be kept pressed. Could someone with knowledge of logic electronics find out what pins I have to bridge to fix this problem. Schematic here. /Hugo

24th May 2009, 02:50 PM	#10
chanwoo diyAudio Member Join Date: Mar 2006 Location: Seoul	I have similar trouble Gentlemen, A year ago, I bought used PR99 and I found something strange as below. I believe someone can explain what happens. 1. When I turn on power SW, it plays automatically regardress tape present. Is this normal? 2. 'PAUSE' butten only working when I holding it down while playing music. And playing again when I release it. Is this normal? 3. I could hear hum from monitoring speaker and it actually amplifying by turning volume when playing PR99 without tape set and I pretty sure it still humming when playing music but can't recongnize because of music. Strangely it's not appear from main speaker. Is someone have an experience about this? Please give me any of your idea or cure. Thank you in advance.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
WTB: Remote Control for Revox B226	Calimero	Swap Meet	6	30th October 2010 11:36 AM
Revox PR99 Input Level Pots	barry.childs	Analogue Source	0	22nd June 2009 06:51 PM
Revox PR99 auto playing when powering up	chanwoo	Analogue Source	0	24th May 2009 02:50 PM
WTB Revox b226/225 remote	propeleris	Swap Meet	0	2nd July 2008 10:55 PM
FS: Revox PR99 parts	ralphs99	Swap Meet	2	23rd May 2008 08:50 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

17th March 2006, 11:22 PM	#2
Ghianni diyAudio Member Join Date: Sep 2005	Hi, I believe that is like Revox A77 dummy connector. Go there http://www.obsoletemedia.com/tapedecks/a77remote.htm perhaps it will help you. Ghianni.

18th March 2006, 08:27 AM	#3
moamps diyAudio Member Join Date: Oct 2002 Location: Croatia	Hi, the standard wired PR99 doesn't need any connector with setting bridges instead of the real remote controller. Your PR is maybe tweaked. Just check Fader Start Logic Pcb for changes. Check also what's source of +24V signal on the pcb for the start signal. Regards, Milan

18th March 2006, 08:56 AM	#4
Netlist diyAudio Moderator Join Date: Jan 2003	Ghianni I found out, as Milan said that no plug is needed in the PR99. Next thing I looked for was the ‘tape end sensor’ and I believe its working properly. Q10 stops conducting when the sensor light is interrupted. The 24V is 28V however. 5V is present. There is no indication of tweaks inside. Looking at the ‘fader start logic’ schematic, I assume K1 is activated when the ‘tape dump' button is pressed. In that condition, the play button stays active. FFW and REW don't work which is a perfectly normal condition. I forgot to tell in my first post that FFW and REW don't stay put as well. My lack of knowledge with ports and logic as used in the 'tape drive control' schematic prevents me from fixing that beauty. /Hugo

18th March 2006, 10:26 AM	#6
Netlist diyAudio Moderator Join Date: Jan 2003	Persistence is sometimes a good thing. A tantalum (again) was short-circuit. For those interested, C2, a 3.3µF cap on the Fader start logic PCB. Thanks for helping. Edit: Milan, thanks for the great offer. I'll remember that. /Hugo

18th March 2006, 11:45 PM	#7
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi Hugo, Yes, the tantalums. I change them out for electrolytics. The dummy plug comment really threw me Hugo! I always forgot to put the A/B-77 plug back in while working on them. I couldn't recall the PR-99 with those memories rolling around. (ever stick the case back on with the dummy plug still in?) Also, the bridge rectifiers tend to overheat. I have installed heatsinks on them in the past with thermal epoxy from Wakefield. The PR-99 was one of my fav machines. Pretty too! -Chris

29th March 2006, 06:18 PM	#8
Netlist diyAudio Moderator Join Date: Jan 2003	Chris, Didn't notice your post till now. That PR99 was in real bad condition. Had been standing for years in a moist area. The cost to repair that would be enormous. The owner is a very caring pro but has no money to store his equipment in a decent garage and even less to pay repairs. So I fixed what had to be fixed and let the rest alone. Nice machine indeed. /Hugo

30th March 2006, 12:12 AM	#9
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi Hugo, What other choice do you have then? I do the same in those situations, or condem the machine. I must admit I'm not nearly as interested in proving I can make junk work anymore! -Chris

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)