ali express super cheap amp - is it possible its 12wpc is 8ohms
-https://www.aliexpress.com/item/1005006746074265.html?spm=a2g0o.detail.pcDetailBottomMoreOtherSeller.94.2ee55DGe5DGeH7&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.40196.394786.0&scm_id=1007.40196.394786.0&scm-url=1007.40196.394786.0&pvid=70cac017-3398-42ef-b6a7-07ee3efdbcba&_t=gps-id😛cDetailBottomMoreOtherSeller,scm-url:1007.40196.394786.0,pvid:70cac017-3398-42ef-b6a7-07ee3efdbcba,tpp_buckets:668%232846%238111%231996&pdp_npi=4%40dis%21GBP%21196.38%2198.19%21%21%211795.06%21897.53%21%4021039c5917249515732538655e0268%2112000038168444962%21rec%21UK%21863394078%21ABX&utparam-url=scene%3ApcDetailBottomMoreOtherSeller%7Cquery_from%3A
-https://www.aliexpress.com/item/1005006746074265.html?spm=a2g0o.detail.pcDetailBottomMoreOtherSeller.94.2ee55DGe5DGeH7&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.40196.394786.0&scm_id=1007.40196.394786.0&scm-url=1007.40196.394786.0&pvid=70cac017-3398-42ef-b6a7-07ee3efdbcba&_t=gps-id😛cDetailBottomMoreOtherSeller,scm-url:1007.40196.394786.0,pvid:70cac017-3398-42ef-b6a7-07ee3efdbcba,tpp_buckets:668%232846%238111%231996&pdp_npi=4%40dis%21GBP%21196.38%2198.19%21%21%211795.06%21897.53%21%4021039c5917249515732538655e0268%2112000038168444962%21rec%21UK%21863394078%21ABX&utparam-url=scene%3ApcDetailBottomMoreOtherSeller%7Cquery_from%3A
It's probably more like 8-10 watts/channel with 6P1P output tubes. And that's on a good day.😉
jeff
It would appear that the output transformers have both 4 & 8 ohms taps, looking at the schematic and pics from your link.
How about 4W? That looks more likely. In general, you get what you pay for. Probably quite a reasonable introduction to valves, but don't expect much.
Using full bridge rectification, the three pentode 6F2 electron tube serves as the 5-pole tube amplification, and the triode serves as the reverse phase push 6P1
I'm wondering what 5-pole tube amplification is, but the reverse phase push is a charming description.
Using full bridge rectification, the three pentode 6F2 electron tube serves as the 5-pole tube amplification, and the triode serves as the reverse phase push 6P1
I'm wondering what 5-pole tube amplification is, but the reverse phase push is a charming description.
jkojic,
That is a very good question!
Before I ever went to marketing, I had Jaded opinions of marketing. (I was an electronic technician, engineer, marketeer, and technical support specialist).
I will get you perhaps up to 10 or 12 Watts out of that amplifier.
I will employ what some marketeers use: hidden lies and hidden secrets.
First of all, that power supply is never going to have enough to be able to get 12 Watts times 2 = 24 Watts.
Can power one channel, but not 2 channels that are both are at 12 Watts each.
Let us assume that we can get a 6 Watt sine wave into an 8 Ohm load, one channel at a time; not both at once.
Rounded numbers:
A 6 Watt sine wave into an 8 Ohm load, is 6.93 Vrms. Sine Wave, No clipping allowed.
6.93 Vrms x 1.414 = 9.8V peak. That is 19.6 V peak to peak, centered around 0 V.
If you badly clip the amplifier output, and make it all the way to 9.8V peak, (19.6 V peak to peak square wave, centered at 0 Volts), that is 12 Watts RMS.
But a square wave is Not Music.
Perhaps that explains the inflated numbers.
Just listen to the amplifier at lower output powers, and you probably will hear music.
That is a very good question!
Before I ever went to marketing, I had Jaded opinions of marketing. (I was an electronic technician, engineer, marketeer, and technical support specialist).
I will get you perhaps up to 10 or 12 Watts out of that amplifier.
I will employ what some marketeers use: hidden lies and hidden secrets.
First of all, that power supply is never going to have enough to be able to get 12 Watts times 2 = 24 Watts.
Can power one channel, but not 2 channels that are both are at 12 Watts each.
Let us assume that we can get a 6 Watt sine wave into an 8 Ohm load, one channel at a time; not both at once.
Rounded numbers:
A 6 Watt sine wave into an 8 Ohm load, is 6.93 Vrms. Sine Wave, No clipping allowed.
6.93 Vrms x 1.414 = 9.8V peak. That is 19.6 V peak to peak, centered around 0 V.
If you badly clip the amplifier output, and make it all the way to 9.8V peak, (19.6 V peak to peak square wave, centered at 0 Volts), that is 12 Watts RMS.
But a square wave is Not Music.
Perhaps that explains the inflated numbers.
Just listen to the amplifier at lower output powers, and you probably will hear music.
I'm going to say no, at least not with the power transformer supplied with that kit.
I have one of the factory ( Meng Yue ? ) made push pull 6P1 amps, and I measured it at about 8 watts per channel with good distortion numbers, IIRC. I looked for the actual numbers in my notebook and could not find them, but I do not recall it getting into double digit watts.
That was with the original Chinese 6P1's of unknown age, as I bought it used to avoid the high cost of shipping. It has slightly larger power and OPT's than the kit you are looking at.
You can get high grade Svetlana 6P1P's all day long, very inexpensively, and I would expect them to be better than the Chinese 6P1's.
Win W5JAG
I have one of the factory ( Meng Yue ? ) made push pull 6P1 amps, and I measured it at about 8 watts per channel with good distortion numbers, IIRC. I looked for the actual numbers in my notebook and could not find them, but I do not recall it getting into double digit watts.
That was with the original Chinese 6P1's of unknown age, as I bought it used to avoid the high cost of shipping. It has slightly larger power and OPT's than the kit you are looking at.
You can get high grade Svetlana 6P1P's all day long, very inexpensively, and I would expect them to be better than the Chinese 6P1's.
Win W5JAG
The links don't take me to the sale site, just a wavy blue line jpg. I did find this:
https://www.aliexpress.us/item/3256805709839387.html?gatewayAdapt=glo2usa4itemAdapt
If that is the same one, with a 240VAC FWB power supply, then B+ could be as high as 300V depending on the RC filter networks. You might be able to get 12W/CH, depending on the rating of the power transformer.
I have squeezed over 15W out of a pair of 6P1P-EV soviet tubes in a guitar amp.
I have gotten 12 w\Ch in a stereo amp using Edcor OPTs and a Toroid power transformer without stressing the tubes. I found the Soviet 6P1P-EV red-plate higher than expected based on the soviet datasheet.
https://www.aliexpress.us/item/3256805709839387.html?gatewayAdapt=glo2usa4itemAdapt
If that is the same one, with a 240VAC FWB power supply, then B+ could be as high as 300V depending on the RC filter networks. You might be able to get 12W/CH, depending on the rating of the power transformer.
I have squeezed over 15W out of a pair of 6P1P-EV soviet tubes in a guitar amp.
I have gotten 12 w\Ch in a stereo amp using Edcor OPTs and a Toroid power transformer without stressing the tubes. I found the Soviet 6P1P-EV red-plate higher than expected based on the soviet datasheet.