OH YEAH! It took me months to come up with that unique designThank you Pete for your help with the heat sinks
OH YEAH! It took me months to come up with that unique designThank you Pete for your help with the heat sinks
I meant to say, I see the deep green color and I was not aware of it before, so maybe that is why it looked toasted. I have a few boards here that are well toasted, that started to look like that, but not because of the factory color being differnt.dark green for the driver
Yes, there is 2 types of driver boards in there. I have a pair that is light color and a pair that is dark green one.to me your driver boards looked diferent from eachother. I do not think is the lighting and I am not looking at the filter board...I am looking at two B-1 driver boards.
Just an observation...
View attachment 1092614
I have seen them come up for sale on the fleabay US and Hong Kong. I got mine on fleabay US. They come in yellow or transparent pastic casing.Pete, where did you source yours from? I also seen that a board can be made and so able to install modern replacements
Yes, there is 2 types of driver boards in there. I have a pair that is light color and a pair that is dark green one.
Managed to finish the boards late last night and do all the adjustments. Everything looks a ok! Adjusted the bias at 80mV and the DC at 0 volt. This is with the SK180 Tokins.
That is a good point, but since I don’t have a curve tracer hard to tell with this batch.That is really good news.
Question: Does SK180 have the same quescent point (~80mV) as the SK77?
You should verrify that.
Congrats, job well doneThat is a good point, but since I don’t have a curve tracer hard to tell with this batch.
I managed to sort out the UC-1 last night. Replaced all the C458 with C1815 and A763 with A1015
For the C1345 I used new C1345F. Meters working well, and was able to calibrate them properly. While I was there pimped it up with some blue LED’s.
At the moment don’t have a distortion meter but was able to do all the calibrations as per manual.
It is middle of summer here and the B-1 gets really hot. Was able to run it for an hour or so and really happy with the results. I will put the SK77 back to do a compare but doing all the work on the drive boards really paid off. The amp sounds sublime
Want to thank you for your help getting the right parts, I decided to get a board for the NF-4 relay. Also changed the ceramic caps on theVfet sinks Panasonic film caps. Here is a pic of the naked beast.
I managed to sort out the UC-1 last night. Replaced all the C458 with C1815 and A763 with A1015
For the C1345 I used new C1345F. Meters working well, and was able to calibrate them properly.
Thank you!Congrats, job well done
The blue lights look a bit alien to me, but that is prolly because my eyes are so used with the B-1, B-2 amber lights.
Nice decor too. Is that 10K a 100v version?
I didn’t change the pots also, but the right meter was not working. Changing the transistors 2 tantalum and all the electrolytic fixed the problem. I cleaned the power switch and is working normally now.I was gonna say, one of my meters was out by 2dBs.
I did not have time to rebuild the UC-1...I will do it next time. I did noticed a bunch of old style 458's in there, so I will definetly bo back in there. I wil not change the pots...the original ones adjusted with no issue.
I will put the SK77 back to do a compare
I too have a unit with green boards. I found that some of the FETs on the green boards might have been replaced on my unitthere is 2 types of driver boards in there. I have a pair that
Green boards...hmmm,
One additional observation:
Does anybody know what TJ08 is...I guess I could answer my own question if I pull it and tested. My guess would be that it is a same channel FET, but is it a close match for the sj24?
I guess I will find out at some point. BTW, both boards have same replacement and both boards come from a unit with a failed SK-180 replacement attempt
This is strange, on one of my boards those transistors were replaced with MPSU60 motorola.I too have a unit with green boards. I found that some of the FETs on the green boards might have been replaced on my unit
Could you please look or send a closup photo of the two round metal can FETs with the black heatsinks on the green driver boards... I do not have a schematic handy and don't recall the component ID
View attachment 1096137
Those two. They are not what the schematic calls for or what my other units have....only noticed them on the green boards. I actually cannot find any information on them.
TJ08, is what they are marked with.
This is strange, on one of my boards those transistors were replaced with MPSU60 motorola.
Yes, 100% I have since pulled them out but am certain about this.Are you sure? Look at it again since that wouldn't work.