Hi,
I have this t.amp 1050 (380W / 8Ohm) specified cheap PA amp. I guess it is a copy of a copy .... and there are many similar amps around, I have attached a schematic I found. I would like to reuse at least the case and the transformer, but I need much better sound 🙂, it should be transferred into a good sounding amp for HiFi.
Do you have any suggestions/schematics for me how to modify it ?
p.s.: I think it needs more than another opamp...
I have this t.amp 1050 (380W / 8Ohm) specified cheap PA amp. I guess it is a copy of a copy .... and there are many similar amps around, I have attached a schematic I found. I would like to reuse at least the case and the transformer, but I need much better sound 🙂, it should be transferred into a good sounding amp for HiFi.
Do you have any suggestions/schematics for me how to modify it ?
p.s.: I think it needs more than another opamp...
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IMO it would require a good bit of modification and I was surprised to find a warning by Toshiba about the output devices liable to failure if run near the top end voltages /current , its not every active device that has this type of warning .
Zenner diodes are well known noise sources , its easy to build a white noise generator using them yet they are connected to the signal input of the output devices --all very well to say-- but at the higher signal voltage it might not matter too much and it is a PA amp anyway but for a low distortion quality amplifier circuit ??
I would redesign the whole lot and put a proper diff pair/vas stage +driver stage in its place but others might have the opposite view ?
Thats if its to be used as a hi-fi amp but if kept as a PA well that's a different matter , if it was a case of a guitar amp then I would go tube.
Zenner diodes are well known noise sources , its easy to build a white noise generator using them yet they are connected to the signal input of the output devices --all very well to say-- but at the higher signal voltage it might not matter too much and it is a PA amp anyway but for a low distortion quality amplifier circuit ??
I would redesign the whole lot and put a proper diff pair/vas stage +driver stage in its place but others might have the opposite view ?
Thats if its to be used as a hi-fi amp but if kept as a PA well that's a different matter , if it was a case of a guitar amp then I would go tube.
Thank you
Should I replace it because of sound quality issues or is it a reliablity problem (I guess both 😀) ?
Should I replace it because of sound quality issues or is it a reliablity problem (I guess both 😀) ?
WHAT do you think you will "improve"? 🙄
Sell/donate it and buy an "Audiophile Approved" expen$$$$$$ive amp 🙄
Be certain to burn it in for 1000 hours first to start improving soundstage, granularity and blackness. 😛
Do what you suggested - reuse the case, transformer, heatsink and the power transistors (IF they are genuine). The circuit itself is crap.
Why do you think so? 'Cause it's a grounded collector amplifier with a floating supply?
As t.amp is an inhouse brand of the German Thomann distributor of musical instruments and gear, the only thing I'd complain is the lack of a VI limiter in a design most probably dedicated to stage use.
Best regards!
I can't find anything bad about the circuit either. Even the components are good. A few years ago, such transistors were only found in high-end amps. The NE5532 may be old and cheap, but it's still very good.
I like the circuit to get the best out of it with as few resources as possible 🙂
As I already mentioned, the relay in such budged devices is often cheap and the contacts burn up relatively quickly. If that is the case, an exchange will have a positive effect ... and not only in the measured values.
The only disadvantage of the grounded collector circuit is that each output stage needs its own power supply. But some high-enders even see it as a special quality standard😉
If you have a lot of leisure, you can swap the bridge rectifier in the power supply for soft recovery types and swap the power supply electrolytic capacitors for very low esr types.
I like the circuit to get the best out of it with as few resources as possible 🙂
As I already mentioned, the relay in such budged devices is often cheap and the contacts burn up relatively quickly. If that is the case, an exchange will have a positive effect ... and not only in the measured values.
The only disadvantage of the grounded collector circuit is that each output stage needs its own power supply. But some high-enders even see it as a special quality standard😉
If you have a lot of leisure, you can swap the bridge rectifier in the power supply for soft recovery types and swap the power supply electrolytic capacitors for very low esr types.