Hey there!
I just finished building a 5E3 Tweed Deluxe clone and it sounds great. Problem is, I'm only getting 9.7 watts out of it. Shouldn't a 5E3 deliver 12 to 14 watts output?
I'm using all American made glass, added a grounded power cord, replaced the ground switch with a standby switch and the filament supply has a center tap which is grounded. All components were tested prior to the build. But I'm only getting 8.8 VRMS across an 8 ohm, non inductive load resistor, at the onset of clipping as seen on my scope.
Below are the voltages I'm getting. What do you think? Is this normal output power for a 5E3?
I just finished building a 5E3 Tweed Deluxe clone and it sounds great. Problem is, I'm only getting 9.7 watts out of it. Shouldn't a 5E3 deliver 12 to 14 watts output?
I'm using all American made glass, added a grounded power cord, replaced the ground switch with a standby switch and the filament supply has a center tap which is grounded. All components were tested prior to the build. But I'm only getting 8.8 VRMS across an 8 ohm, non inductive load resistor, at the onset of clipping as seen on my scope.
Below are the voltages I'm getting. What do you think? Is this normal output power for a 5E3?
An externally hosted image should be here but it was not working when we last tested it.
Perhaps the original output transformer has higher performance than you use. And the output power in the guitar amp depends on which guitar / microphone you connect. Gibson humbucker has much more output than single coil fender.
I think all DC volt lock ok.
I think all DC volt lock ok.
Can you get 8.8v RMS across your 8R speaker?
P = I2 * R
R = 8R therefore I = 1.1.
1.21A * R = 9.68Watts. RMS or 1.414 * 9.68 = 13.68Watts p-p
P = I2 * R
R = 8R therefore I = 1.1.
1.21A * R = 9.68Watts. RMS or 1.414 * 9.68 = 13.68Watts p-p
Thank you for the replies!
True, the output transformer may be lacking for this application. It was an economy model. I was testing the amp on my bench with a signal generator, into a load bank.
You gave me something to really think about, JonSnell. I went back and retested using the 8 ohm speaker for the load. With a 500Hz sine wave, I'm getting 12 VRMS across the speaker. (At the edge of clipping.) If the reactive load is still 8 ohms at 500Hz, that looks like about 18 watts. It looks like my amp is close to spec. Yes, my ears are ringing. 😱
True, the output transformer may be lacking for this application. It was an economy model. I was testing the amp on my bench with a signal generator, into a load bank.
You gave me something to really think about, JonSnell. I went back and retested using the 8 ohm speaker for the load. With a 500Hz sine wave, I'm getting 12 VRMS across the speaker. (At the edge of clipping.) If the reactive load is still 8 ohms at 500Hz, that looks like about 18 watts. It looks like my amp is close to spec. Yes, my ears are ringing. 😱
I see that your concerns have been put to rest already. 🙂
I was going to comment that 9.7 watts instead of 12W is only 0.9 dB lower. One decibel is about the smallest detectable change in signal level, so the drop from 12W to 9.7 W is essentially inaudible.
Even if you compare 9.7 watts against your higher number (14 W), that's still only a 1.6 dB loss. That's still a barely audible change.
Please take good care of those ears! Loudness-induced hearing loss is cumulative - you do more damage to your hearing every time you listen to something loud enough to cause ringing ears. Then, one day, you hear a small jet-plane taking off inside your ear(s) - and the sound never stops. 😱
-Gnobuddy
IMO measuring clean power output of a guitar amp, is of little more than academic value. Especially for amps like the 5E3 or Marshall 18W which people usually want for their cranked distortion sounds. It turns out that the Marshall can only put out 13W clean, but who cares. They're loud and distort beautifully.
Regarding the OT you're using, it turns out that the original 5E3 OT is being used well beyond its ratings and is close to blowing up. We found this out when I was working for a boutique guitar amp company that had a 5E3 clone in its product range.
Sent from my phone. Please excuse any typpos.
Regarding the OT you're using, it turns out that the original 5E3 OT is being used well beyond its ratings and is close to blowing up. We found this out when I was working for a boutique guitar amp company that had a 5E3 clone in its product range.
Sent from my phone. Please excuse any typpos.
- Status
- Not open for further replies.