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Hey 2250B and 2275 owners! Pop on power down
- Thread starter rBuckner
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@jholdahl, I am assuming that the "pop" that you refer to is heard through the speakers.
- Do you hear the pop on both speakers?
- Do you hear the pop then relay click, or relay click then pop?
- Do you hear it if you turn the volume all the way down? (From you other post it sounds like it gets louder with higher volume.)
- Have you replaced any components on the P800 Power Supply board?
- Plug a stereo RCA cable into the Main In jacks only, leave the other end open and try it again. Does it still pop?
- If the pop goes away with the volume turned all the way down, or when you do the above test, then it is occurring in the Pre-amp.
- Does it do it for all selector inputs AM/FM/Phono/Aux/Tape? What about if you push the Tape Mon button in?
Last edited:
jholdahl
New Member
Thanks @dankik! This is thing is special to me so I’m pretty invested in squashing this final bug.
1. Pop on power down in both speakers, yep. I hear it through both speakers and headphones but my speakers (a diy job with JBL 328c drivers via Ojas) are quite sensitive so the power down pop tends to be more noticeable through them as opposed to my kind of cruddy headphones fwiw.
2. Essentially simultaneous on power down! Doesn’t pop on power up really at all, although small note on that below.
3. At no volume during power down, yes, the pop goes away. Pop loudness is proportionate to where the volume pot sits on power down (unless either or both mono switches are depressed; then it goes away althoghter). And sorry for double posting :E
4. Yes, I replaced a ton on this unit. The pop was there before during and after the refurb fwiw although it’s a bit more potent/robust after refurb. Did the full refurbishment of P800 according to the great instructions and kit and recent troubleshooting help supplied by Affinity for Artifacts, along with all other boards and main filter caps (save for PT01, which isn’t really on anyone’s refurb list, but also happens to be where the Mono switches that also stop the power down pop reside). Lights and display were the first piece of the puzzle redone before the other boards with gracious advice and supply from @dgwojo and new 3d printed housings from n0ufx on the auction site to replace the melted and warped originals. Did all the electrolytic caps plus diodes and transistors where instructed, and the relay on P800 but no resistors/trimmers. Built a dim bulb and used it at each step all the way thru, but no issues came up during test iterations along the way. Voltage, bias, offset have all been brought to spec according to standard procedures. When redoing PE01 preamp, FYI I swapped in the spendy but sparklin’ Sparkos BA 312 kit, which did include some resistor removal and recap around the new adaptive modules and one replaced resistor at RE73.
A post by Tom @catrafter in the other thread points to R813 on P800 needing a bump up in resistance on the relay to give the amps time to normalize before the relay clicks, but this would seem to be more applicable to both Power Up and Power Down. I’ll say this makes sense to me as I did notice that once I did the main filter caps the relay closes more quickly post-refurb, particularly noticeable after I redid the main filter caps. In new news, if I cycle on/off quickly, I can sometimes also get it to pop when turning on. That’s where Ben from Affinity for Artifacts and I narrowed down the problem to be together. I’m nabbing the relevant resistors from Mouser now, to attempt at stepping up from 240k to 390k to see if this silences the power down pop by delaying the relay. Could there de a stray lead somewhere? Possibly? But I’ve jiggled, wiggled, and cleaned so much and was so careful/anal that I kind of doubt it.
5. It does not pop with an open ended RCA cable.
6. Understood. This is kind of the limit of my recently acquired knowledge. And I am really curious how the Mono switches interrelate to the PE01 board. When engaged, do their resistors somehow slow the relay down just enough to silence the pop on power down?
7. It happens on all inputs, yes. Tape monitor button did not eliminate the pop. Only the mono switches seem to do it :/
I also tried the power switch test, with the unit on a power strip/wifi smart plug to see if that was the problem, but the pop remains either way.
Tons of appreciation for the various restoration threads here from @thxdave @Super Noob @MarantzRefrb and others I’m unfortunately forgetting, and elsewhere on YT with blueglow, ah fix it, etc etc. Any other recommendations or troubleshooting steps other than stepping up resistance on R813? Can’t wait to get over the line with this thing.
Thanks in advance for any help you can provide.
1. Pop on power down in both speakers, yep. I hear it through both speakers and headphones but my speakers (a diy job with JBL 328c drivers via Ojas) are quite sensitive so the power down pop tends to be more noticeable through them as opposed to my kind of cruddy headphones fwiw.
2. Essentially simultaneous on power down! Doesn’t pop on power up really at all, although small note on that below.
3. At no volume during power down, yes, the pop goes away. Pop loudness is proportionate to where the volume pot sits on power down (unless either or both mono switches are depressed; then it goes away althoghter). And sorry for double posting :E
4. Yes, I replaced a ton on this unit. The pop was there before during and after the refurb fwiw although it’s a bit more potent/robust after refurb. Did the full refurbishment of P800 according to the great instructions and kit and recent troubleshooting help supplied by Affinity for Artifacts, along with all other boards and main filter caps (save for PT01, which isn’t really on anyone’s refurb list, but also happens to be where the Mono switches that also stop the power down pop reside). Lights and display were the first piece of the puzzle redone before the other boards with gracious advice and supply from @dgwojo and new 3d printed housings from n0ufx on the auction site to replace the melted and warped originals. Did all the electrolytic caps plus diodes and transistors where instructed, and the relay on P800 but no resistors/trimmers. Built a dim bulb and used it at each step all the way thru, but no issues came up during test iterations along the way. Voltage, bias, offset have all been brought to spec according to standard procedures. When redoing PE01 preamp, FYI I swapped in the spendy but sparklin’ Sparkos BA 312 kit, which did include some resistor removal and recap around the new adaptive modules and one replaced resistor at RE73.
A post by Tom @catrafter in the other thread points to R813 on P800 needing a bump up in resistance on the relay to give the amps time to normalize before the relay clicks, but this would seem to be more applicable to both Power Up and Power Down. I’ll say this makes sense to me as I did notice that once I did the main filter caps the relay closes more quickly post-refurb, particularly noticeable after I redid the main filter caps. In new news, if I cycle on/off quickly, I can sometimes also get it to pop when turning on. That’s where Ben from Affinity for Artifacts and I narrowed down the problem to be together. I’m nabbing the relevant resistors from Mouser now, to attempt at stepping up from 240k to 390k to see if this silences the power down pop by delaying the relay. Could there de a stray lead somewhere? Possibly? But I’ve jiggled, wiggled, and cleaned so much and was so careful/anal that I kind of doubt it.
5. It does not pop with an open ended RCA cable.
6. Understood. This is kind of the limit of my recently acquired knowledge. And I am really curious how the Mono switches interrelate to the PE01 board. When engaged, do their resistors somehow slow the relay down just enough to silence the pop on power down?
7. It happens on all inputs, yes. Tape monitor button did not eliminate the pop. Only the mono switches seem to do it :/
I also tried the power switch test, with the unit on a power strip/wifi smart plug to see if that was the problem, but the pop remains either way.
Tons of appreciation for the various restoration threads here from @thxdave @Super Noob @MarantzRefrb and others I’m unfortunately forgetting, and elsewhere on YT with blueglow, ah fix it, etc etc. Any other recommendations or troubleshooting steps other than stepping up resistance on R813? Can’t wait to get over the line with this thing.
Thanks in advance for any help you can provide.
I did find that it was due to the BA312 IC on the tone control board. Some do it, some do not. I just rebuilt a 2275 and it doesn't pop on power down. They used too high of a value resistor for the biasing on these ICs and I changed it from whatever it was, I think 680K, down to 220K. These are RE11 and RE12 and the schem sows them at 1 Meg. That may or may not help.
jholdahl
New Member
Thanks @rBuckner! I’m sure you know Sparkos kit requires a lot of resistor removal, including RE11 and RE12, so they’re not on my PE01 board anymore.
I’ve got a line into Sparkos to see if they’ve encountered this before and if is interrelated.
I’ve got a line into Sparkos to see if they’ve encountered this before and if is interrelated.
Yes, I've used those once or twice, but it's been a long time ago, so I don't recall what, if any, popping issues were solved or created.
On the power on popping, the current one does it and I've had to up the timing resistor to delay the relay engagement on these before so will be doing it again.