Ultraphonix adventure
Moderators: pompeiisneaks, Colossal
Ultraphonix adventure
On the local offerings i found one modded bassman SF for not so much, several hundreds. Immediately i bought it over the phone without too much thinking about condition inside. Price for the amp is now in thousands. It was just important that it original output transformer inside.
10 yrs ago nobody wanted bassman, it was almost for free. How the situation is changing..
10 yrs ago nobody wanted bassman, it was almost for free. How the situation is changing..
- Reeltarded
- Posts: 9964
- Joined: Sat Feb 14, 2009 4:38 am
- Location: GA USA
Re: Ultraphonix adventure
I sold a load of combos and several heads in the last ten years. The truth isn't pretty. Very few people are buying but the prices are being listed higher and higher.
There are still $1000-1500 BF Bassman heads around here. People are wrecking the market with prices only the novice would even inquire about.
Let's hear that mod!! lol
Mine is going to be tubes up in a JTM45 reissue.
There are still $1000-1500 BF Bassman heads around here. People are wrecking the market with prices only the novice would even inquire about.
Let's hear that mod!! lol
Mine is going to be tubes up in a JTM45 reissue.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
Re: Ultraphonix adventure
Provided schematic are not so good guide, moreover it is just needed to put mental set in that Marshall sound base (or boosted JTM45)..
I have found some good infos looking at the pics here, what is possible to detect, other by assumption.
https://ampgarage.com/forum/viewtopic.php?f=5&t=20544
So if we go from the output we can see JTM45 with 6L6's. Or bassman 5F6A. I made many, and it is by default creamy sound, nice cleans Fender, and creamy overdrive when pushed. Phase inverter is classic, no surprises there. Sound is in the first 2 tubes V1 and V2.
I have found some good infos looking at the pics here, what is possible to detect, other by assumption.
https://ampgarage.com/forum/viewtopic.php?f=5&t=20544
So if we go from the output we can see JTM45 with 6L6's. Or bassman 5F6A. I made many, and it is by default creamy sound, nice cleans Fender, and creamy overdrive when pushed. Phase inverter is classic, no surprises there. Sound is in the first 2 tubes V1 and V2.
Re: Ultraphonix adventure
in Europe BF is around 2-2.5k , 10 yrs ago it was for 300-400 max nobody wanted , because is "only" bassman. But this "only" bassman is actually great for usReeltarded wrote: ↑Wed Jan 11, 2023 11:46 am I sold a load of combos and several heads in the last ten years. The truth isn't pretty. Very few people are buying but the prices are being listed higher and higher.
There are still $1000-1500 BF Bassman heads around here. People are wrecking the market with prices only the novice would even inquire about.
Let's hear that mod!! lol
Mine is going to be tubes up in a JTM45 reissue.
But is little bit too much to invest 1.5k to take cab, chassis and tranformers, sadly..
Re: Ultraphonix adventure
So i bought this.. this is some kind of "blackface" bild on SF chassis. sort of
outside was looking ok, except for this fake plate By looking at, guess of job reconstruction, i can see that chassis was cleaned totally, transformers, capacitor covers, polished ! This is a moment for alarm, who wants to polish all this things. You can just reduce value, not add. Inside mix of all kind of components on old eyelett board, new wires but burned everywhere by soldering iron ( ). Good skills by sevice tech. Grounded coax, soldered to chassis (!!) for PI input wire! For which reason, there is allready hi level of signal! Burned completelly heater wires. To the exposed copper. Genious again. Why he remove cloth heater wire which is kind of soldering iron resistant and put new ones PVC, and burned them throughly?
On bias circuit also one russian MF resistor find its place. 2 print "buck" transformers to raise 320VAC secondary to 344. Power transformer i see that was wound, by clumsy lamination assembly and strange wire colors from it.
OPT looks ok. Choke is some very ugly , looks like DIY, and will be replaced, with green wires! Green! Green cannot pass here.
Cab is great if i can say so. Job done is far from good, it is assembled without taking care of anything. But i like this projects, to reconstruct from the 0, i have all mechanical jobs finished, so 2-3 days of pleasure work for new electronics.
inside:
outside was looking ok, except for this fake plate By looking at, guess of job reconstruction, i can see that chassis was cleaned totally, transformers, capacitor covers, polished ! This is a moment for alarm, who wants to polish all this things. You can just reduce value, not add. Inside mix of all kind of components on old eyelett board, new wires but burned everywhere by soldering iron ( ). Good skills by sevice tech. Grounded coax, soldered to chassis (!!) for PI input wire! For which reason, there is allready hi level of signal! Burned completelly heater wires. To the exposed copper. Genious again. Why he remove cloth heater wire which is kind of soldering iron resistant and put new ones PVC, and burned them throughly?
On bias circuit also one russian MF resistor find its place. 2 print "buck" transformers to raise 320VAC secondary to 344. Power transformer i see that was wound, by clumsy lamination assembly and strange wire colors from it.
OPT looks ok. Choke is some very ugly , looks like DIY, and will be replaced, with green wires! Green! Green cannot pass here.
Cab is great if i can say so. Job done is far from good, it is assembled without taking care of anything. But i like this projects, to reconstruct from the 0, i have all mechanical jobs finished, so 2-3 days of pleasure work for new electronics.
inside:
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Re: Ultraphonix adventure
By double holes on everything i can conclude also chassis is "borowed" from some other amp, maybe bandmaster.. At least he put Bassman OT correct. This is important part. Lets go on. Everything dismantled. Boards are very dirty from resin, and needs to be cleaned..
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Re: Ultraphonix adventure
removed parts
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Re: Ultraphonix adventure
i will reuse Atom cathode elkos from this pile ..
Went to home store and bought some heavy chemicals to start with boards, petrol and acetone for cleaning
Went to home store and bought some heavy chemicals to start with boards, petrol and acetone for cleaning
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Re: Ultraphonix adventure
after several turns, petrol, scratching, acetone, scratching on repeat, i get some ok results.
stage between, grease destroyed, but still there, ready for another round:
stage between, grease destroyed, but still there, ready for another round:
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Re: Ultraphonix adventure
board ready :
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Re: Ultraphonix adventure
botom isolating board , passed through the same process..but here were dicovered some other things..
board before cleaning, full of resin: but after the cleaning, holes discovered, looks like board wasnt isolating the rest of the circuit from chassis, looks like this one was passing current holes cleaned with grinder and filled with wife's nail laquer
board before cleaning, full of resin: but after the cleaning, holes discovered, looks like board wasnt isolating the rest of the circuit from chassis, looks like this one was passing current holes cleaned with grinder and filled with wife's nail laquer
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Re: Ultraphonix adventure
I didnt like that the boards from pressed paper were prone to so much humidity and possible short circuits risk so i decided to varnish all with plastic spray.
The rectifier board passed the same process. Assembly started with HER 208 fast diodes.
The rectifier board passed the same process. Assembly started with HER 208 fast diodes.
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Re: Ultraphonix adventure
assembly started, chosen German resistors, metal film MK3 Roe, carbon film Draloric LCA.. caps 6PS's , around PI 715's.
Carbon comps on PI, i saw that HAD have more CC on PI but i thought the sound will be too dark. So Dralorics LCA.
Carbon comps on PI, i saw that HAD have more CC on PI but i thought the sound will be too dark. So Dralorics LCA.
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Re: Ultraphonix adventure
next boards varnished for protection with Plastic spray:
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Re: Ultraphonix adventure
arrived the time to fix that wiring.. i have some stash of solid core cloth wire, perfect for old Fenders..taken signals for tone stack on gain and clean channel, also NFB and output grid wires
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