sweetbeats
Reel deep thoughts...
What's happening with the RT-707? 
analogkid
I Bleed Analog!
The tape slides toward the faceplate when you first engage it and twists up, plus the speeds vary badly - i can hear the warbling. I have tried to adjust the takeup and back tension etc but doesn't seem to do any good. I tired swapping the pinch roller from the other, working RT-707 but it didn't help. I had planned to have Terry Witt re-rubber the pinch rollers for both; looks like I will send this one in next month and do the other one after I get the new roller back. MAYBE it's only the pinch roller..... or maybe the capstan is too smooth, but I'm thinking it is far more likely that the motors are beginning to go - these are all direct drive motors no belts except for the tape counter. I can only estimate the hours on this deck, but 800-1000 is seriously possible. How much is 4 hours a night average for 10-12 years? my calculator says 780, so figure realistically 800 hours!
AK
AK
sweetbeats
Reel deep thoughts...
I'm diving in now with two feet...
My bass player friend leaves for a mission in northern Africa very soon...he is visiting me next Thursday. Strike when the iron is hot.
I've asked him to lay bass tracks during his visit for the demo project that has been waiting in the wings for my 58 to be ready. The artist has been quite patient, but agrees that it would be worth the wait. Well, I don't want the project to hang until my friend's return from Africa...I'm going to try and schedule for my client to lay scratch tracks before next Thursday, even if they have to go to the DAW. Hoping to arrange to borrow the oscilloscope from Ethan before Thursday next week to check and adjust the bias circuitry (Ethan, I'll PM you...)
Here's my biggest challenge/question. I've stated earlier how clear its become that the analog mixing console is essential in tracking to an atr. I don't have one, at least not one that is going to be ready to go by Thursday. In the digital world all we need in the signal chain is the head amp since the A/D converter won't tolerate anything over 0dBu anyway, but that doesn't work when tracking to analog, at least not for me. No flexibility in that, and a noise-floor that is much too close. My only mixer is the Yamaha 01X...its digital...no good for this...
What do I do? I will likely be using my Presonus Digimax FS as a preamp. it was inserts and direct outs on every channel plus ADAT I/O, so it will serve well as an analog mic pre while sending backup to the DAW (not wanting to display lack of confidence in the 58, but it is my first flight...) I need a device to control (boost) the signel level coming out of the Digimax to the 58...I have access to an old Biamp mixing board...actually has some nice features...I'm familiar with it as I've done some repair work on it, but I've also been told to run, and run fast from the Biamp board in terms of signal quality. I also have my MX-80...I realize that this would not be the proper application for that, but I need something...
Suggestions? Brainstorming ideas?
My bass player friend leaves for a mission in northern Africa very soon...he is visiting me next Thursday. Strike when the iron is hot.
I've asked him to lay bass tracks during his visit for the demo project that has been waiting in the wings for my 58 to be ready. The artist has been quite patient, but agrees that it would be worth the wait. Well, I don't want the project to hang until my friend's return from Africa...I'm going to try and schedule for my client to lay scratch tracks before next Thursday, even if they have to go to the DAW. Hoping to arrange to borrow the oscilloscope from Ethan before Thursday next week to check and adjust the bias circuitry (Ethan, I'll PM you...)
Here's my biggest challenge/question. I've stated earlier how clear its become that the analog mixing console is essential in tracking to an atr. I don't have one, at least not one that is going to be ready to go by Thursday. In the digital world all we need in the signal chain is the head amp since the A/D converter won't tolerate anything over 0dBu anyway, but that doesn't work when tracking to analog, at least not for me. No flexibility in that, and a noise-floor that is much too close. My only mixer is the Yamaha 01X...its digital...no good for this...
What do I do? I will likely be using my Presonus Digimax FS as a preamp. it was inserts and direct outs on every channel plus ADAT I/O, so it will serve well as an analog mic pre while sending backup to the DAW (not wanting to display lack of confidence in the 58, but it is my first flight...) I need a device to control (boost) the signel level coming out of the Digimax to the 58...I have access to an old Biamp mixing board...actually has some nice features...I'm familiar with it as I've done some repair work on it, but I've also been told to run, and run fast from the Biamp board in terms of signal quality. I also have my MX-80...I realize that this would not be the proper application for that, but I need something...
Suggestions? Brainstorming ideas?
ethyrvalve
Norman Nanoweber
hmmm I'd perhaps keep my eyes peeled for a dbx163 or 163x compressor. They're usually very cheap ($40-60ish) and I find they work great as bass direct boxes (even if you'd rather not compress the bass). You could patch it directly into the 58.
Just an idea...
Just an idea...
sweetbeats
Reel deep thoughts...
I have 6 channels of analog compression that I'm really happy with, especially with bass. What I need is something that will serve the role of a channel fader to have control of and boost the signal to tape.
I could use the MX-80, though it is a mic preamp, not a line amp. What would really fit the bill would be an M-1...but the MX-80 has a 30dB pad on it, so it would work level-wise, but it is a mic pad rather than a switch that routes the signal through a line amp...probably wouldn't be the cleanest...
I need this for all 8 tracks, and not just for tracking the bass as it is going to be a bit before the M-520 is in production.
I could use the MX-80, though it is a mic preamp, not a line amp. What would really fit the bill would be an M-1...but the MX-80 has a 30dB pad on it, so it would work level-wise, but it is a mic pad rather than a switch that routes the signal through a line amp...probably wouldn't be the cleanest...
I need this for all 8 tracks, and not just for tracking the bass as it is going to be a bit before the M-520 is in production.
A Reel Person
It's Too Funky in Here!!!
sweetbeats
Reel deep thoughts...
Dave, yeah, that's kind of what I'm thinking...my only concern is that, based on the manual for the MX-80 and just looking at the unit, it is intended to be a mic preamp and 8X2 mixer only, not a line amp...so you have all that head amp circuitry that the signal goes through, and undesireable artifacts will be introduced by sending a line-level signal through a microphone head amp. Would I/could I hear the difference?? Dunno, but I've got so many new variables floating around on this project and I hate to introduce more...want to keep things as simple and normal as I can. If only the MX-80 was a mic/line mixer and the pad switch actually bypassed the head amp.
To make matters worse, that old Biamp mixing board I mentioned earlier, a 1224, is not available at this time...
Maybe I need to just knuckle down and get 8 channels of the M-520 cleaned up and functioning right...just use the direct outs...4 are done but I have yet to test them. Sounds silly to not just do that but you'd have to understand my situation that once the M-520 gets moved into my cave-esque control room it will be very difficult to continue the cleanup process just because the space is so cramped. I wanted to get it all cleaned up first before I move it in there, which is going to be a bear in and of itself...plus my patchbays are still pulled apart, the 58 is not yet ready...everything is still in flux. Once I finished my last project I started transitioning the studio from all digital to hybrid and it is completely in the middle...the M-520 is sitting in a faux recording/repair space at the moment in the same area as the cave so it wouldn't be too bad to have to walk back and forth and deal with the limited cable runs (recall that I am considering using the Presonus Digimax FS as a preamp but I'll have to see when we setup for the session...I have no experience with the M-520 pre's and I've never recorded the artist before so its unknown at this point...) Hm. Maybe this will work now that I'm thinking "out-loud"...I'll have to ponder it more. It could be done...firewire cables will reach, the RC-51 remote will reach...snakes will reach...Hm...It would just mean that the partially assembled M-520 would be parked in the same space as the artist along with my I/O rack (which is on wheels, so that's not that big a deal), and then the 58 and the monitors would be in the "control room". I'd use the 01X to control monitor levels to the speakers in the control room when I'm in there, and use headphones when out in the recording space when setting levels and such. With the RC-51 I'd be able to control the transport from the recording space and then interface directly with the deck when in the control room...it could work...not ideal at all, but it could work and I could get the project rolling using the appropriate gear, just in an unorthodox manner.
To make matters worse, that old Biamp mixing board I mentioned earlier, a 1224, is not available at this time...
Maybe I need to just knuckle down and get 8 channels of the M-520 cleaned up and functioning right...just use the direct outs...4 are done but I have yet to test them. Sounds silly to not just do that but you'd have to understand my situation that once the M-520 gets moved into my cave-esque control room it will be very difficult to continue the cleanup process just because the space is so cramped. I wanted to get it all cleaned up first before I move it in there, which is going to be a bear in and of itself...plus my patchbays are still pulled apart, the 58 is not yet ready...everything is still in flux. Once I finished my last project I started transitioning the studio from all digital to hybrid and it is completely in the middle...the M-520 is sitting in a faux recording/repair space at the moment in the same area as the cave so it wouldn't be too bad to have to walk back and forth and deal with the limited cable runs (recall that I am considering using the Presonus Digimax FS as a preamp but I'll have to see when we setup for the session...I have no experience with the M-520 pre's and I've never recorded the artist before so its unknown at this point...) Hm. Maybe this will work now that I'm thinking "out-loud"...I'll have to ponder it more. It could be done...firewire cables will reach, the RC-51 remote will reach...snakes will reach...Hm...It would just mean that the partially assembled M-520 would be parked in the same space as the artist along with my I/O rack (which is on wheels, so that's not that big a deal), and then the 58 and the monitors would be in the "control room". I'd use the 01X to control monitor levels to the speakers in the control room when I'm in there, and use headphones when out in the recording space when setting levels and such. With the RC-51 I'd be able to control the transport from the recording space and then interface directly with the deck when in the control room...it could work...not ideal at all, but it could work and I could get the project rolling using the appropriate gear, just in an unorthodox manner.
sweetbeats
Reel deep thoughts...
I hope I'm doing my math wrong...
So I've got evm1024's super-cool Tektronix 465 o'scope in my studio...Thank you Ethan!
I read some educational material to which Ethan directed me. I looked that over, and set the scope up in the house with a tone generator. Read pertinent sections of the manual, and after fiddling around for about an hour figured out how to measure frequency and amplitude. Cool.
Brought out here, hooked it up to the appropriate test points on an amp card to test the naster bias oscillator frequency, and I hope in my over-confidence Izm doing the math wrong...
I have a probe connect to channel one, vertical mode is set to channel one, VOLTS/DIV is set to .1, TIME/DIV is set to 1 micro-second. I pull in a good sweep, and measure one cycle at about 3.4 divisions...that's...294kHz right?
About double the 145kHz it is supposed to be...
Don't know where to go from here...don't know if it is a problem with the master bias oscillator, or components on the master bias card...
Tracking session is in about 42 hours...this is nuts.
So I've got evm1024's super-cool Tektronix 465 o'scope in my studio...Thank you Ethan!
I read some educational material to which Ethan directed me. I looked that over, and set the scope up in the house with a tone generator. Read pertinent sections of the manual, and after fiddling around for about an hour figured out how to measure frequency and amplitude. Cool.
Brought out here, hooked it up to the appropriate test points on an amp card to test the naster bias oscillator frequency, and I hope in my over-confidence Izm doing the math wrong...
I have a probe connect to channel one, vertical mode is set to channel one, VOLTS/DIV is set to .1, TIME/DIV is set to 1 micro-second. I pull in a good sweep, and measure one cycle at about 3.4 divisions...that's...294kHz right?
About double the 145kHz it is supposed to be...Don't know where to go from here...don't know if it is a problem with the master bias oscillator, or components on the master bias card...
Tracking session is in about 42 hours...this is nuts.
sweetbeats
Reel deep thoughts...
I just toasted my 58...
....................
After the last post I decided to check what the sweep looked like on the bias oscillator on my 48. It also reads 294kHz which is just too much of a coincidence so I must be doing the math wrong. Brought the scope back over to the 58 to start check bias traps, assuming that the oscillator frequency is correct...pulled amp card #8 (with power off). Connected amp card to extender card...didn't see that it was offset by one pin...turned on power. Meter #8 totally pegged, peak LED lit solid, bad click sound...quickly shut off deck. Reseat amp card on extender card properly, turn on power. everything looks okay until I realize nothing at all lights up on the arming panel. Reel motors don't spin...one pin...one careless pin.
I check fuses, two bad ones. I replace but same symptoms exist. Amp card #8 looks okay but smells a little funny...this is really sad.
I am totally...over...whelmed.
....................
After the last post I decided to check what the sweep looked like on the bias oscillator on my 48. It also reads 294kHz which is just too much of a coincidence so I must be doing the math wrong. Brought the scope back over to the 58 to start check bias traps, assuming that the oscillator frequency is correct...pulled amp card #8 (with power off). Connected amp card to extender card...didn't see that it was offset by one pin...turned on power. Meter #8 totally pegged, peak LED lit solid, bad click sound...quickly shut off deck. Reseat amp card on extender card properly, turn on power. everything looks okay until I realize nothing at all lights up on the arming panel. Reel motors don't spin...one pin...one careless pin.
I check fuses, two bad ones. I replace but same symptoms exist. Amp card #8 looks okay but smells a little funny...this is really sad.
I am totally...over...whelmed.
ethyrvalve
Norman Nanoweber
What a drag cory. Just remind yourself that once you've got it working, it's gonna be a tank. My 58 hasn't given me any sass at all in a year of pretty heavy use.
Have you tried removing all the amp cards? Perhaps there's an arc in there somewhere?
Have you tried removing all the amp cards? Perhaps there's an arc in there somewhere?
evm1024
New member
Ouch
OK, was it offset one pin to the left or one pin to the right? We can decide what was shorted there. Also, which fuses were blown? Test each fuse as that a blown fuse may not be obvious from instpection (if it blows inside the link.)
We want to makesure that you have each voltage.
Back to the scope - I assume that you counted the divisions from one rising edge zero crossing point to the next rising edge crossing point. If you measure from a rising to a falling you would get twice the frequency.
All is not lost....as long as it is not slag you can put it right.
-Ethan
OK, was it offset one pin to the left or one pin to the right? We can decide what was shorted there. Also, which fuses were blown? Test each fuse as that a blown fuse may not be obvious from instpection (if it blows inside the link.)
We want to makesure that you have each voltage.
Back to the scope - I assume that you counted the divisions from one rising edge zero crossing point to the next rising edge crossing point. If you measure from a rising to a falling you would get twice the frequency.
All is not lost....as long as it is not slag you can put it right.
-Ethan
analogkid
I Bleed Analog!
Sorry to hear that man. I did something similar to my Revox PR99 recently; everything was working except the unit would not stay in 'play'... shorted the wrong two terminals and PFFFT. Now nothing works at all. But I have a spare for parts, and I am digging out all my old electronics books... I'll get it going again, and you'll get your 58 going again. Anything we can do to help you out man, we are here!
AK
AK
sweetbeats
Reel deep thoughts...
Pete, Ethan, AK...thank you. I can't tell you how valuable your encouragement and advice is. Really. Its just scary because I don't have the knowledge or experience for this level of troubleshooting or repair, don't want to ship it anywhere and can't afford to pay for the service elsewhere. I am confident that I can get it going with help, and I'm seeing the help already so thank you so much. 
Pete, great suggestion. I pulled all 8 cards as well as the master bias card (didn't think that would have an effect because its upstream, but, again, with my limited knowledge I figured it couldn't hurt to pull it...), but the conditions remain.
Ah, I guess that would be offset one pin to the left, or down as it is oriented in the deck. Picture below.
F2 and F3, both the rec/repro amp fuses.
Yes. Thanks for that reminder. They are all good.
Do you mean measure from each fuse holder to ground and make sure each rail is functioning? Since the scope is here is there any advantage to using that to see if the voltages are stable?
I do believe I went rise to rise (or rather I think I did fall to fall). Picture below, and again that is at 1µs. Its about 3.4 divisions to my eyes. Am I reading that correctly?
FYI, I got the reels off the deck to confirm the reel motor malfunction...in EDIT mode nothing spins (capstan is okay, and servo control is working fine because the pitch control is working), but the shutoff sensor is working, and the pinch roller engages in PLAY, just no reel motor activity, and no LED's function on the arming panel. I have not done any testing to see if it is still passing audio.
Pete, great suggestion. I pulled all 8 cards as well as the master bias card (didn't think that would have an effect because its upstream, but, again, with my limited knowledge I figured it couldn't hurt to pull it...), but the conditions remain.
Ah, I guess that would be offset one pin to the left, or down as it is oriented in the deck. Picture below.
F2 and F3, both the rec/repro amp fuses.
Yes. Thanks for that reminder. They are all good.
Do you mean measure from each fuse holder to ground and make sure each rail is functioning? Since the scope is here is there any advantage to using that to see if the voltages are stable?
I do believe I went rise to rise (or rather I think I did fall to fall). Picture below, and again that is at 1µs. Its about 3.4 divisions to my eyes. Am I reading that correctly?
FYI, I got the reels off the deck to confirm the reel motor malfunction...in EDIT mode nothing spins (capstan is okay, and servo control is working fine because the pitch control is working), but the shutoff sensor is working, and the pinch roller engages in PLAY, just no reel motor activity, and no LED's function on the arming panel. I have not done any testing to see if it is still passing audio.
Attachments
evm1024
New member
Ok
Rise to rise, 3.4 uS +-.... we can look at that later.
Next step it to look at the voltages from the power supply and make sure that they are all there.
Here are some places to look on the PS board.
pin 11 +15
pin 10 -15
pin 5 +24
pin 19 +24
pin 28 +24
pin 27 +15
pin 26 +5
You should check these voltages. They are referenced to ground.
On the extender card you can check for some voltages....
pin 1 +15
pin 4 -15
pin 12 +24
pin 21 +15
pin 22 -15
This would be a good start.
Rise to rise, 3.4 uS +-.... we can look at that later.
Next step it to look at the voltages from the power supply and make sure that they are all there.
Here are some places to look on the PS board.
pin 11 +15
pin 10 -15
pin 5 +24
pin 19 +24
pin 28 +24
pin 27 +15
pin 26 +5
You should check these voltages. They are referenced to ground.
On the extender card you can check for some voltages....
pin 1 +15
pin 4 -15
pin 12 +24
pin 21 +15
pin 22 -15
This would be a good start.
evm1024
New member
off hand....
Off hand the biggest problem (if you are lucky) is that Q5 is blown up (in the PS). That is the regulated +24 supply measured on PS pin 5 or repro card pin 12. By offsetting your card you shorted the +24 to ground. Which is actually good....
It looks like most if not all of the other problems would be confined to a single rec/repro card (at least one can hope).
-Ethan
Sick Joke: wanna trade for a 38?
Off hand the biggest problem (if you are lucky) is that Q5 is blown up (in the PS). That is the regulated +24 supply measured on PS pin 5 or repro card pin 12. By offsetting your card you shorted the +24 to ground. Which is actually good....
It looks like most if not all of the other problems would be confined to a single rec/repro card (at least one can hope).
-Ethan
Sick Joke: wanna trade for a 38?
sweetbeats
Reel deep thoughts...
Awesome. Thanks Ethan. I want to learn from this too so I will backtrack in the schematics from what you are saying to check to get more familiar.
I'm on it! er...after work.
I like beige...
If Q5 is blown, that should be a readily available part right? Just reference the 2SD-313E description from the manual?
I'm on it! er...after work.
I like beige...
If Q5 is blown, that should be a readily available part right? Just reference the 2SD-313E description from the manual?
evm1024
New member
Beige, brown whats the diff?
Yup, (you can leave off the dash). The 2SD313E is an NPN Si power transistor.
2SD is a standard Asian designation kinda like 2n....
There most likely would be other blown things....But, getting the voltages in spec is the first step.
-E
Awesome. Thanks Ethan. I want to learn from this too so I will backtrack in the schematics from what you are saying to check to get more familiar.
I'm on it! er...after work.
I like beige...
If Q5 is blown, that should be a readily available part right? Just reference the 2SD-313E description from the manual?
Yup, (you can leave off the dash). The 2SD313E is an NPN Si power transistor.
2SD is a standard Asian designation kinda like 2n....
There most likely would be other blown things....But, getting the voltages in spec is the first step.
-E
sweetbeats
Reel deep thoughts...
I'm trying to color-match
The M-520 has beige all over it...so does the ES-50 and 51...the carpet has a lot of beige in it...Who cares how it performs, man. Its all in the color.
The M-520 has beige all over it...so does the ES-50 and 51...the carpet has a lot of beige in it...Who cares how it performs, man. Its all in the color.
sweetbeats
Reel deep thoughts...
Did some probing...
I started by checking the amp card supply pins. This is how it started on #8:
pin 1 +15 good
pin 4 -15 good
pin 12 +24 good
pin 21 +15 bad
pin 22 -15 good
Then by the time I got to card #5 I had nothing on pin 22...then card #4 I had nothing on pins 1 or 4 either, pin 12 +24 was the only pin showing voltage. I put the extender card back in slot 8 and it was the same (only pin 12 showing voltage).
Hm, I thought.
Turned the deck around and checked the power supply:
pin 11 +15 bad
pin 10 -15 bad
pin 5 +24 good
pin 19 +24 good (but putting out about +27.5)
pin 28 +24 good (but putting out about +31.6)
pin 27 +15 bad
pin 26 +5 good
Hm...yeah...check the fuses again...all good except, of course, F2 and F3.
I'm intuitively guessing I'll be pulling that PSU PCB out of the deck...and am I correct that there must be stuff downstream that is blown because the fuses keep blowing?
I'm concerned that the reel motors aren't functioning since the +24 rails seem alive, although those two are pretty hot...bad caps? But I suppose the sensors run on the 15 +/- rails...I'll be studying the schematics later.
I started by checking the amp card supply pins. This is how it started on #8:
pin 1 +15 good
pin 4 -15 good
pin 12 +24 good
pin 21 +15 bad
pin 22 -15 good
Then by the time I got to card #5 I had nothing on pin 22...then card #4 I had nothing on pins 1 or 4 either, pin 12 +24 was the only pin showing voltage. I put the extender card back in slot 8 and it was the same (only pin 12 showing voltage).
Hm, I thought.
Turned the deck around and checked the power supply:
pin 11 +15 bad
pin 10 -15 bad
pin 5 +24 good
pin 19 +24 good (but putting out about +27.5)
pin 28 +24 good (but putting out about +31.6)
pin 27 +15 bad
pin 26 +5 good
Hm...yeah...check the fuses again...all good except, of course, F2 and F3.
I'm intuitively guessing I'll be pulling that PSU PCB out of the deck...and am I correct that there must be stuff downstream that is blown because the fuses keep blowing?
I'm concerned that the reel motors aren't functioning since the +24 rails seem alive, although those two are pretty hot...bad caps? But I suppose the sensors run on the 15 +/- rails...I'll be studying the schematics later.
evm1024
New member
divide and ....
Just need to pull The PS connector and then check the PS voltages. Could be something outside of the PS or the PS itself. If it is the PS then fix that. Then power up each subsystem one at a time....
Yes, study the schematic and make deductions and formulate a test to check them out.
There is a regulated and an unregulated 24 volt supply. It would not be at all out of line for an unregulated supply to run 20%high.
-Ethan
Just need to pull The PS connector and then check the PS voltages. Could be something outside of the PS or the PS itself. If it is the PS then fix that. Then power up each subsystem one at a time....
Yes, study the schematic and make deductions and formulate a test to check them out.
There is a regulated and an unregulated 24 volt supply. It would not be at all out of line for an unregulated supply to run 20%high.
-Ethan