So I believe I had this amp,bought it in the late 70's, used it till it went out in the late 80's. I thought I remembered it rated at 50 wps and also having a start up breaker that took like 5 seconds till it would click and let sound on. I didn't see that with yours here. Great video and thanks.
I was told those sleeves you find on power resistors are intumescent and supposed to stop open flaming in the event of failure. Could be a fun experiment to see if they work.
I have the 6500 which I have been using for about 6 months or so and now plan on refreshing - caps etc., so this should be an interesting watch. Thx for video!
48:58 These are indeed full bridge incadescent replacements designed specifically to run on AC or DC supplies of vintage gear. Fitted these to a lot of Marantz 22s, no flicker and in warm white, truly indistinguishable from original. There's a Bulgarian outlet in everyone's favourite place with make and model specific sets available. Cannot recommend enough.
@@TrevorsBench 4 years of daily use on one of them, so looks like they were built to last. Have you managed to trace the overshoot? I cannot remember exactly, but going from 220 to 330p on the RC to gnd upstream of the LTP input solved similar issue I've had. Entire compliment of one channel minus the LTP was blown to bits and following replacement, developed a bit of overshoot. Bo the pre and power sections were testing percectly fine on their own, but once coupled, that spike was there. Funnily enough, both channels were re-done with exactly the same and matched compliment. i guess no matter how close you get in terms of equivalence, differences in junction capacitances can make it frustrating. Anyhow, I really enjoyed this one, that damn scr, eh?
Problems like that drive me crazy ! You replaced all the parts, swapped parts around and it got better as it warmed up but that's not really what you want. You need to be sure that there are no problems before letting it out of your care otherwise it makes you look bad ! It seemed to me like it might have been in the tone circuit but can't imagine what it might be, I hope you find it !
I found a dodgy resistor in the feedback loop of that channel. It was a odd value, 110k ohms and was out of tolerance. I replaced them in both channels with two 220k resistors in parallel. I didn't show it in the vid but I fixed this when I went back in to adjust the meter lamp brightness. Just goes to show how sharp my viewers really are!
Will putting a thin coat of ox guard on all the legs of the output transistors keep them from corroding inside the sockets they use that on aluminum on your electrical wiring on your main cable coming into your house and on commercial buildings
Too bad they didn't include high pass filtering. Maybe the next models do. Well, replacing the fuse as I am sure you know Trevor that doesn't negate the issue with why. 😂 See these caps...you know what I 'm thinking.... So, Trevor I'm going to assume you'll rectify the bare wire wrapped with tape etc. You, may, as we aren't at the end yet but to err on the side of caution I'd replace the drive transistors.
I don't believe that the blown meter lamps that you pulled out were original; they were covered with green Mylar sleeving that would typically be on AKAI lamps (and on a few other makes but not Pioneer). It gives a nice subtle green glow. I wish that I could find a source for purchasing some stock but I've never been able to find it.
You may be right. Blue or green filament tinted lamps are near impossible to find. One can replicate the colour with LEDs and colour film and lots of experimentation. One of my viewers, Mark in Wisconsin, turned me on to LED filament lamps that can replicate the light pretty close. I found them on Aliexpress, search for "COB LED Filament"
Long road to hoe on this one Trevor hope my SA 6800 with the Blue vacuum lighting, I like it, very simple design, does not have any issues like this. Agree with how power transistors connect to the board, using a torch on those new power transistors, high risk, I know it is the only way, why not de-solder the old Bat wings?. However surprised the Diodes failed (Check Va. of Electronic flow). Words cannot express how I hate idiots that do 1/2 ass lighting. Original lighting mounted to VU Meters, WHY? Did not look like Fun, do like the reflect the light philosophy. WTH, cut the Yellow jumper. 50W output, not bad since rated at 45W
Hi Robert, You can't desolder the old batwings, they are a molded 1 piece transistor. The torch was no problem, they can handle a lot more heat than what I used. The original rectifier diodes are rated at 2A, I replaced them with 6A diodes
Check your local electronics store or check audio forums for any recommendations. For example I service a large portion of the PNW and then maybe 10% is shipped to me from other states like Utah, North Dakota, and a couple of other Midwest states. Unfortunately I’m about 8 months out at the moment. I’d recommend jumping onto audiokarma and asking there, I’m sure someone can get you into touch with a skilled technician.
I could have but Pioneer already had a circuit dedicated to controlling the lamp current. I just made some adjustments to that circuit to adapt to the lower current LEDs
Wait, I thought I read that you reported somebody for having too long of a video. That would be impossible. It would take a special kind of jerk to do that.
Man the physical condition of these gears you've been getting is quite well preserved.
Wow Trevor, quite a battle. This project would have ended with me practicing my shot putting skills! LOL
So I believe I had this amp,bought it in the late 70's, used it till it went out in the late 80's. I thought I remembered it rated at 50 wps and also having a start up breaker that took like 5 seconds till it would click and let sound on. I didn't see that with yours here. Great video and thanks.
Very good output transistors, they resist the torch!
Thanks for the video! Really enjoyed watching it!
I was told those sleeves you find on power resistors are intumescent and supposed to stop open flaming in the event of failure. Could be a fun experiment to see if they work.
Sorta like heat wraps on exhaust manifolds then? That makes a lot of sense, actually❤
It's annoying because it covers the markings and makes the resistance checks a chore
Nice looking integrated amp.
The meters (and backlighting mod) make it so.
That amp is a beast for 40 a side.
I have the 6500 which I have been using for about 6 months or so and now plan on refreshing - caps etc., so this should be an interesting watch. Thx for video!
48:58 These are indeed full bridge incadescent replacements designed specifically to run on AC or DC supplies of vintage gear. Fitted these to a lot of Marantz 22s, no flicker and in warm white, truly indistinguishable from original. There's a Bulgarian outlet in everyone's favourite place with make and model specific sets available. Cannot recommend enough.
Thanks, they look like a good alternative to using incandescents. I will look at stocking some of these for future projects
@@TrevorsBench 4 years of daily use on one of them, so looks like they were built to last. Have you managed to trace the overshoot? I cannot remember exactly, but going from 220 to 330p on the RC to gnd upstream of the LTP input solved similar issue I've had. Entire compliment of one channel minus the LTP was blown to bits and following replacement, developed a bit of overshoot. Bo the pre and power sections were testing percectly fine on their own, but once coupled, that spike was there. Funnily enough, both channels were re-done with exactly the same and matched compliment. i guess no matter how close you get in terms of equivalence, differences in junction capacitances can make it frustrating. Anyhow, I really enjoyed this one, that damn scr, eh?
Problems like that drive me crazy !
You replaced all the parts, swapped parts around and it got better as it warmed up but that's not really what you want. You need to be sure that there are no problems before letting it out of your care otherwise it makes you look bad ! It seemed to me like it might have been in the tone circuit but can't imagine what it might be, I hope you find it !
I found a dodgy resistor in the feedback loop of that channel. It was a odd value, 110k ohms and was out of tolerance. I replaced them in both channels with two 220k resistors in parallel. I didn't show it in the vid but I fixed this when I went back in to adjust the meter lamp brightness.
Just goes to show how sharp my viewers really are!
A rare Xerox branded custom Fluke meter made for Xerox, So cool!
Will putting a thin coat of ox guard on all the legs of the output transistors keep them from corroding inside the sockets they use that on aluminum on your electrical wiring on your main cable coming into your house and on commercial buildings
Too bad they didn't include high pass filtering. Maybe the next models do. Well, replacing the fuse as I am sure you know Trevor that doesn't negate the issue with why. 😂 See these caps...you know what I 'm thinking.... So, Trevor I'm going to assume you'll rectify the bare wire wrapped with tape etc. You, may, as we aren't at the end yet but to err on the side of caution I'd replace the drive transistors.
Pioneer always do better when they warm up, I have a crazy one off Marantz amp that needs repair if you are interested? Thankyou
At about 1:18:22, that left channel square wave briefly improved, not sure what you did, but maybe that could be a clue to the problem?
I don't believe that the blown meter lamps that you pulled out were original; they were covered with green Mylar sleeving that would typically be on AKAI lamps (and on a few other makes but not Pioneer). It gives a nice subtle green glow. I wish that I could find a source for purchasing some stock but I've never been able to find it.
You may be right. Blue or green filament tinted lamps are near impossible to find. One can replicate the colour with LEDs and colour film and lots of experimentation.
One of my viewers, Mark in Wisconsin, turned me on to LED filament lamps that can replicate the light pretty close.
I found them on Aliexpress, search for "COB LED Filament"
Long road to hoe on this one Trevor hope my SA 6800 with the Blue vacuum lighting, I like it, very simple design, does not have any issues like this. Agree with how power transistors connect to the board, using a torch on those new power transistors, high risk, I know it is the only way, why not de-solder the old Bat wings?. However surprised the Diodes failed (Check Va. of Electronic flow). Words cannot express how I hate idiots that do 1/2 ass lighting. Original lighting mounted to VU Meters, WHY? Did not look like Fun, do like the reflect the light philosophy. WTH, cut the Yellow jumper. 50W output, not bad since rated at 45W
Hi Robert, You can't desolder the old batwings, they are a molded 1 piece transistor. The torch was no problem, they can handle a lot more heat than what I used.
The original rectifier diodes are rated at 2A, I replaced them with 6A diodes
@@TrevorsBench 10-4
Another chnange all the capacitor video gerry-rig all the semiconductor because you can't get the orginal parts
Thanks again for watching
Trevor,
Do you take repairs work from the USA?
Last I heard no
@@danielknepper6884the postage will be really high & is also a high risk IIRC
No, sorry. Too much here already from my local clients. They already face a 2 month wait for return
Check your local electronics store or check audio forums for any recommendations. For example I service a large portion of the PNW and then maybe 10% is shipped to me from other states like Utah, North Dakota, and a couple of other Midwest states. Unfortunately I’m about 8 months out at the moment. I’d recommend jumping onto audiokarma and asking there, I’m sure someone can get you into touch with a skilled technician.
Could you not just add an in-line resistor right before feeding power to the lamps...one on each ? Even a VR to dial the intensity up or down?
I could have but Pioneer already had a circuit dedicated to controlling the lamp current. I just made some adjustments to that circuit to adapt to the lower current LEDs
VIDEO IS WAY TOO LONG REPORTED
Wait, I thought I read that you reported somebody for having too long of a video. That would be impossible. It would take a special kind of jerk to do that.
What the hell is wrong with you, you comment this crap under every video on this channel. Don't watch it then.
This is when Pioneer started cost cutting. Vinyl wrapping, ribbon wire.
I thought it was the flouroscan era that was cost cutting?