Try to lower transformer noise
I just bought a used tube amp
It’s the Boyuu model ???
What I’m thinking of is this
McIntosh pure’s hot tar into the input and output transformers. I guess that’s how they get them not to have any harmonic or subharmonic vibration. I was wondering if y’all can tell from this picture if I could do this to these type of transformers. Or is anyone done anything like this? I know I’m giving a lot of vague information , as I just picked this up a few hours ago
Thanks and please do t be to hard on my ignorance. Lol
Also. Any advice on what kind of different tubes I could use in this? I will pull the tubes out and get the model and make of them . and I have one more sheet about this amp,I can take a picture of it if that helps
Thanks
I just bought a used tube amp
It’s the Boyuu model ???
What I’m thinking of is this
McIntosh pure’s hot tar into the input and output transformers. I guess that’s how they get them not to have any harmonic or subharmonic vibration. I was wondering if y’all can tell from this picture if I could do this to these type of transformers. Or is anyone done anything like this? I know I’m giving a lot of vague information , as I just picked this up a few hours ago
Thanks and please do t be to hard on my ignorance. Lol
Also. Any advice on what kind of different tubes I could use in this? I will pull the tubes out and get the model and make of them . and I have one more sheet about this amp,I can take a picture of it if that helps
Thanks
There are no input transformers in your amplifier, just one power transformer and two output transformers.
Are the transformers making noise now? If not, I hardly believe that treating them the way you propose will give improvement of some sort.
Some remarks about the writing on the schematic:
- I advise you not to discharge the capacitors in the power supply by 'grounding them out' because that is bad for the capacitors. A good solution for this is permanently soldering in a resistor of 330K (2 Watt) parallel to C301 (or C302) so the capacitors discharge every time you switch off the amplifier.
- The suggested capacitor of 0.027 uF between pins 2 and 4 of the 6N9JP will screw up the high frequency response of your amplifier.
Are the transformers making noise now? If not, I hardly believe that treating them the way you propose will give improvement of some sort.
Some remarks about the writing on the schematic:
- I advise you not to discharge the capacitors in the power supply by 'grounding them out' because that is bad for the capacitors. A good solution for this is permanently soldering in a resistor of 330K (2 Watt) parallel to C301 (or C302) so the capacitors discharge every time you switch off the amplifier.
- The suggested capacitor of 0.027 uF between pins 2 and 4 of the 6N9JP will screw up the high frequency response of your amplifier.
From what the guy told me is this
He bought a diy kit ( that’s what the papers are from. The amp I bought was a pre built unit. That he bought to use as he was building his kit. I think I’ll pull the bottom cover off and take some photos and post them on this post. I really don’t know squat about building tube amps.
Hopefully I can show in the photos , if the wiring is like the papers he gave me. Fingers crossed that it’s done properly.
On about filling the output trans with tar like
McIntosh does with their amps. I just thought that it would help. But like I stated, I’m a newbie. I did flick the covers of them and they sound hollow , and that’s when I remembered that video from McIntosh, showing them filling theres with tar. McIntosh saying that that helped with the sound. In a day or two I’ll post some pics with the bottom cover off. And I’ll find some info from the web
Thanks for your help and info.
He bought a diy kit ( that’s what the papers are from. The amp I bought was a pre built unit. That he bought to use as he was building his kit. I think I’ll pull the bottom cover off and take some photos and post them on this post. I really don’t know squat about building tube amps.
Hopefully I can show in the photos , if the wiring is like the papers he gave me. Fingers crossed that it’s done properly.
On about filling the output trans with tar like
McIntosh does with their amps. I just thought that it would help. But like I stated, I’m a newbie. I did flick the covers of them and they sound hollow , and that’s when I remembered that video from McIntosh, showing them filling theres with tar. McIntosh saying that that helped with the sound. In a day or two I’ll post some pics with the bottom cover off. And I’ll find some info from the web
Thanks for your help and info.
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If you can hear the transformers vibrating than something has to be done including filling them ... but fist you have to check the origin of the noise by taking them apart as much as possible
Output transformers do not vibrate, the current thru them is pretty constant. The power transformer can vibrate but usually that is bad in a toroid and not so with EI types which you have here.
Is it not simply 60Hz hum you are hearing? If you unplug the speaker is the sound still present? (Unplug the speakers for a brief moment while it is on then plug speakers back on before turning it off.)
60Hz hum is due to magnetic coupling of the closely placed transformers. Some shielding may help. Rotating the transformer may help as well.
If the hum is 120Hz it is ripple on your high voltage rail coming thru the circuit. Several various remedies for that. Must have picture of internals for more trouble shooting.
Is it not simply 60Hz hum you are hearing? If you unplug the speaker is the sound still present? (Unplug the speakers for a brief moment while it is on then plug speakers back on before turning it off.)
60Hz hum is due to magnetic coupling of the closely placed transformers. Some shielding may help. Rotating the transformer may help as well.
If the hum is 120Hz it is ripple on your high voltage rail coming thru the circuit. Several various remedies for that. Must have picture of internals for more trouble shooting.
Potting the transformers from a Chinese amp in tar is not going to magically transformer a Chinese amp into a McIntosh. This is like bolting a wing onto an 88 Honda Civic and calling it a formula 1 race car.
It would really help to know if there's an actual issue with the amp.
Are they getting hot? Get a screwdriver, stick the thick end against your ear and the pointy end on each tfmr in turn, what do you hear?
You can tighten EI type tfmr's bolts to reduce noise and also fit rubber mounting grommets, if these tfmrs are marginal, chance is they'll run a bit hot and if thrown together be noisy. Also worth taking a bolt out to see if the bolt shaft is insulated, it should be if not it will form a shorted turn.
So, test em, whip em out and try tightening the bolts after checking they're insulated and checking for other faults like trapped wires etc. If they're getting hot potting them will make things worse, so whilst your at it check what current the amp is drawing, leaky caps can form a short = more current draw = more noise/heat.
Andy.
You can tighten EI type tfmr's bolts to reduce noise and also fit rubber mounting grommets, if these tfmrs are marginal, chance is they'll run a bit hot and if thrown together be noisy. Also worth taking a bolt out to see if the bolt shaft is insulated, it should be if not it will form a shorted turn.
So, test em, whip em out and try tightening the bolts after checking they're insulated and checking for other faults like trapped wires etc. If they're getting hot potting them will make things worse, so whilst your at it check what current the amp is drawing, leaky caps can form a short = more current draw = more noise/heat.
Andy.
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