Looking thru my shed I have found a heap of caps, heatsinks and trannies, I am offering the person who is willing to help me fix this sucker anything they want from the pile within the value of their labour.
Caps are 33000uF monsters and there are 6 of them 63Volt rated
(NOS)
I was thinking of making a subwoofer amp but now know I don't yet have the skilss and equipment you need to work on electronics
After my attempts to build a chip amp I'm scared of stuffing up the pre-amp completely
Regards
Ted
Caps are 33000uF monsters and there are 6 of them 63Volt rated
(NOS)
I was thinking of making a subwoofer amp but now know I don't yet have the skilss and equipment you need to work on electronics
After my attempts to build a chip amp I'm scared of stuffing up the pre-amp completely
Regards
Ted
Honestly don't know.
But much better when just turned on and cold, the longer the pre-amp is turned on and the higher the temperature the lower the volume, it is much better with the case mods for ventilation but after 10 / 12 hours it is still b***y hot and output drops.
I'd strat saving for a new pre-amp but this one shoul be fixable and I like its phono inputs, I also like its inverting outputs when I use it without the electronic XO
But much better when just turned on and cold, the longer the pre-amp is turned on and the higher the temperature the lower the volume, it is much better with the case mods for ventilation but after 10 / 12 hours it is still b***y hot and output drops.
I'd strat saving for a new pre-amp but this one shoul be fixable and I like its phono inputs, I also like its inverting outputs when I use it without the electronic XO
Hi Elki, you need 4 caps to replace the original Yamaha caps.
I will have 2 spare
I haven't replaced them yet, we have been too busy moving house
If the two (2) I have are of use to you they are yours for postage plus what I paid
This problem seems to be directly related to the heat in my unit
I will have 2 spare
I haven't replaced them yet, we have been too busy moving house
If the two (2) I have are of use to you they are yours for postage plus what I paid
This problem seems to be directly related to the heat in my unit
Try this link
Seem to be still available in packs of 6
http://cgi.ebay.com/New-6-of-6800uF...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262
Seem to be still available in packs of 6
http://cgi.ebay.com/New-6-of-6800uF...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262
Long time waiting
Well after moving house and all that I finally got some help with a soldering iron.
Reworked what appeared to be some dry solder joints and replaced the 35V 4500uF caps with the bigger units.
The sound is back, a noticeable difference, I may now have to spray the case and make it look pretty again
Well after moving house and all that I finally got some help with a soldering iron.
Reworked what appeared to be some dry solder joints and replaced the 35V 4500uF caps with the bigger units.
The sound is back, a noticeable difference, I may now have to spray the case and make it look pretty again
well...the specific model suffers a number of problems and has been cured a few times in my shop ...
electrolytic caps fail in the power supply area and you will notice that the phenomeno is epidemic .... many 47 mf will need to be replaced ( especially if the unit has been runing under thermal stress or Ta above 25 for long time )
then again trimers might be broken and/or leacky but most of all switches and pots need to be cleaned ...
finally to make sure on how you re going to work the best method will be to isolate the problem versus the area hapening fix it and then consider any upgrades
schematic is available if you wish to have it e mail me ( 18Mb)
kind regards sakis
electrolytic caps fail in the power supply area and you will notice that the phenomeno is epidemic .... many 47 mf will need to be replaced ( especially if the unit has been runing under thermal stress or Ta above 25 for long time )
then again trimers might be broken and/or leacky but most of all switches and pots need to be cleaned ...
finally to make sure on how you re going to work the best method will be to isolate the problem versus the area hapening fix it and then consider any upgrades
schematic is available if you wish to have it e mail me ( 18Mb)
kind regards sakis
2 caps r spare
I put them in the swap section but no takers, if anybody needs these two caps speak up please.
All the problems seen to have been fixed if not solved. dry solder joints on the outputs re-done.
All in all it was easy but scary.
These do run much cooler now with the holes in the case and the extra heatsinking on the Class-A stage.
Thanx to everybody who helped.
I may now have to revisit that chip amp I started
I put them in the swap section but no takers, if anybody needs these two caps speak up please.
All the problems seen to have been fixed if not solved. dry solder joints on the outputs re-done.
All in all it was easy but scary.
These do run much cooler now with the holes in the case and the extra heatsinking on the Class-A stage.
Thanx to everybody who helped.
I may now have to revisit that chip amp I started
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.