Low Heater Readings

[jckid649]

I was noticing my express build was sounding very harsh and the distortion was very ugly. I did some troubleshooting and found that all my voltage readings were fine, but I was not getting any readings from any of the heaters on any pre-amp or power tube. Any thoughts on this?

[Kassie]

I was noticing my express build was sounding very harsh and the distortion was very ugly. I did some troubleshooting and found that all my voltage readings were fine, but I was not getting any readings from any of the heaters on any pre-amp or power tube. Any thoughts on this?

You had your multimeter on ACV? If the heaters are not working... i don't think you'll be getting any sound at all.

[jckid649]

I was noticing my express build was sounding very harsh and the distortion was very ugly. I did some troubleshooting and found that all my voltage readings were fine, but I was not getting any readings from any of the heaters on any pre-amp or power tube. Any thoughts on this?

You had your multimeter on ACV? If the heaters are not working... i don't think you'll be getting any sound at all.

Sorry I had it on the wrong setting. However, it is only reading 2.6v at all the heaters.

[jckid649]

delete

[ampgeek]

Low current draw through the tube often leads to high plate voltages.

Dave O.

[jckid649]

Looks like the reading was fine. Again I had the meter on the wrong setting. But it still doesn't account for the low heater voltages. I know those are right.

[jckid649]

I disconnected the heater taps from the power tubes and each wire reads 2.8v. So does that mean my PT is bad?

[Tillydog]

I disconnected the heater taps from the power tubes and each wire reads 2.8v. So does that mean my PT is bad?

Set the meter to AC volts and connect one lead from the meter to each heater wire (not heater wire and ground).

What do you read?

[jckid649]

I disconnected the heater taps from the power tubes and each wire reads 2.8v. So does that mean my PT is bad?

Set the meter to AC volts and connect one lead from the meter to each heater wire (not heater wire and ground).

What do you read?

5.7v

[Kassie]

I disconnected the heater taps from the power tubes and each wire reads 2.8v. So does that mean my PT is bad?

Set the meter to AC volts and connect one lead from the meter to each heater wire (not heater wire and ground).

What do you read?

5.7v

5.7 is nothing to worry about.. the tubes gladly run on anything between 5 and 6.3 ac.

What AC are you reading at the PT secondaries.. and what DC are you reading at the diodes? And DC across the 9k1 resistors? Then read what you get in the preamp B's. If that's all fine then your powersupply and PT is OK.

[jckid649]

Set the meter to AC volts and connect one lead from the meter to each heater wire (not heater wire and ground).

What do you read?

5.7v

5.7 is nothing to worry about.. the tubes gladly run on anything between 5 and 6.3 ac.

What AC are you reading at the PT secondaries.. and what DC are you reading at the diodes? And DC across the 9k1 resistors? Then read what you get in the preamp B's. If that's all fine then your powersupply and PT is OK.

All other measurements and readings are within tolerance. I was kind of wondering about that. I figured if it was too low it should reduce the volume of the amp, but the thing is louder than hell's hallway. I guess I just need to work on lead dress and such to iron out the harshness.

[Kassie]

All other measurements and readings are within tolerance. I was kind of wondering about that. I figured if it was too low it should reduce the volume of the amp, but the thing is louder than hell's hallway. I guess I just need to work on lead dress and such to iron out the harshness.

How would you describe the harsh distortion then? Is it similar to a lot of demo's on youtube or different? How is your clean sound when you roll the guitar volume pot?

[jckid649]

All other measurements and readings are within tolerance. I was kind of wondering about that. I figured if it was too low it should reduce the volume of the amp, but the thing is louder than hell's hallway. I guess I just need to work on lead dress and such to iron out the harshness.

How would you describe the harsh distortion then? Is it similar to a lot of demo's on youtube or different? How is your clean sound when you roll the guitar volume pot?

It's hard to describe. The clean sound is very nice and the distortion sounds fine until you crank the volume really high and then it just seems overpowering. Gets harder to hear the articulation of individual notes the more overdrive you dial in.

[jjman]

If the reading is correct there is a problem. Could be in the heater section or elsewhere bringing the heater winding down.

[Kassie]

It's hard to describe. The clean sound is very nice and the distortion sounds fine until you crank the volume really high and then it just seems overpowering. Gets harder to hear the articulation of individual notes the more overdrive you dial in.

Ok, I don't see any strange things yet. Clean is nice... so there is probably no fundamental flaw in your circuit. With my express I never go past 3 o clock... I reckon at 3 o clock my clean is not so nice anymore when rolling with the guitarvolume. Past 3 o clock it really starts to become mushy. Because it's serious gain territory. I usually have the ampvolume at 12 or 1 o clock. Try tweaking the mid and bass knobs... and experiment with the bright switch... 100pf tightens things up somewhat in the high gain territory. As always, the more gain the less definition.

What kind and how many speakers are you using? are you using a volumemod in your build? What cab?