Tweet
This is a long shot but here goes.....Does anybody here happen to have any pics of the inside of this??I had this dropped off to me for repair and the owner had bought this on Reverb.com a few months back.....The sound was very distorted and I found a 1k/10W resistor that was open and causing no screen voltage to the output tubes...........replaced it and the amp now works but very poorly...all kinds of buzzing which increases with the volume control......looks like this was repaired before and all the biasing circuitry has been changed and a pot has been cemented to the inside of the chassis.....with a resistor added to one of the end terminals....two flimsly red wires running back to the ckt board and a very long tie strip which has a bunch of elect caps and resistors all glued together for what must be the power supply....when I go back to the shop after, I will take some pics and upload them here for your viewing pleasure...there is no way this can be factory......anyway, I will be back later.....
-
-
"I took a photo of my ohm meter... It didn't help." Enzo 8/20/22 -
Thanks for the reply...That is the schematic that I have....pics attached.....
Comment
-
Curious, what are the output tubes? Looks like its been modded with an adjustable bias and someone replaced the screen resistors with 1k'sComment
-
Yeh it looks like a cob job BUT the musical question is "does it function?" I'm simultaneously amused and appalled by that collection DC balancing resistors perched atop what appears to be a pair of filter caps in series. Same for the gobs 'o glue.Originally posted by bsco View Post
Since I'm not satisfied with the unsatisfactory reliability of CE multisection caps, and haven't yet tried and tested the rival multisection choice Hayseed Hamfest, I often replace multisections with individual caps. Who knows, the tech who rebuilt the power surprise in this B15 may have been in a similar frame of mind. And/or has the "go with what you got" attitude - get it working with what's available & avoid importing expensive & tariff-taxed parts.
Consider what Forrest Gump would have said if he was an amp tech: "Fixin' amps is like a box of choc'lits. When you open one up, you never know what you'll find."
This isn't the future I signed up for.Comment
-
It does work but not very well......I did have an open 1k/10W resistor for the screen voltage supply line...I might have to tear out all the stuff for the power supply and I would love to get it back to the original looks....that is why I was wondering if somebody had any pics or even a pictorial layout...The owner is going to drop by tonight to have a look and let me know what he wants to do....and you are probably right on the use what you got attitude...I once had an amp that had a bunch of resistors with the leads twisted together in order to get the correct value that was needed...not just two resistors but a dozen or more...if the owner wants to proceed then so be it.....I will try my best....Comment
-
I think the output tubes are a 6L6 type version....maybe the industrial type.......when I get over to the shop this evening I will double check and let you know.....I forgot to ask...is there another Ampeg flip top series that might use a similar power supply setup as this one...if I could find a pic of the guts it might be a big help....never mind. I just did another search on the net and found some pics.....this amp really has been torn apart...there has been a lot of work done on this in the past.....the inside of this one looks nothing like it is supposed to.....I will keep you posted.....Originally posted by tdlunsfo View PostLast edited by bsco; 11-05-2020, 02:04 PM.Comment
-
This gut shot said it was of a B15S after a cap job.
When the going gets weird... The weird turn pro!Comment
-
Thank you very much for that pic.....what a difference...that is what I will have to do with this or at least as close as I can...as it stands now, anything would be an improvement over what has been done....where did you find this pic??Comment
-
When the going gets weird... The weird turn pro!Comment
Comment