Attenuators?? Any guys use them here with MV amps?

[steve_k]

Sorry, I should have been a touch clearer in my earlier post. It's not that there is a load issue in using one. It is more along the line of using the amplifier in a full power mode for extended periods of time. It is more of a heat diffusing issue. Many people tend to think they can crank the power section to full then cut it to where they need the db level to be for quiet situations. The problem that occurs is that transformers use copper wire and if placed in an overheat situation for too long the transformer will suffer damage. This also can happen without an attenuator if the amp is played maxed for way to long. The end result will be a dulling of the sound either way. Yes I agree with you that a well designed power section should be able to be dimed for the life of an amp but we all know the unfortunate reality of cost effective manufacturing. Thank you for redirecting my error.

No doubt, running anything at maximum capacity will reduce the life expectancy. The PT has nothing to do with it. It pumps out B+ voltage, irregardless of the volume. The OT takes the brunt of the onslaught. It's not the copper windings in the OT that will fail or the metal core. Metal is metal and for the most part, rust comes with age and rust is a good thing. It's the paper insulation and lead dress that one would be concerned about, especially in older transformers that have been exposed to moisture, etc. An OT will get weak and fail over time due to the insulation degradation. Excessive heat loss from the OT is an indicator, as is the tone degradation. Or, the lead wire dress, especially the cloth stuff becomes brittle with age and can cause more of a catastrophic failure. These 30-35 year old Marshalls with original OT's, I am sure were never contemplated by Jim. If I could bring about a failure, it just gives me a good reason to change out to some Mercury or Merrin iron.

There are some differences on loading the amp using a power attenuator or loading the amp using the FX loop. The attenuator is loading the amp at the end of the line, so to speak, at the speaker output. This is seeing all the A/B nature of the power tubes, fluctuating voltage and exposes every component of the amp to that brick wall of variable resistance. Depending on the type and placement of the FX loop in relation to the MV, this will have a different effect on the components being loaded.

 

[stephen sawall]

I melted the wax in the transformer of a vintage Fender ~ dime & boosting the front end big time. The wax dripped down and also messed up the speaker .... I was not using a attenuator. It happens....
As it was melting it was one the best tones I have ever got..... amazing actually. Swansong -Everyone noticed the sound / tone .... then the smoke. The power tube was actually almost white when I looked at the back as I was unplugging it from the wall....

 

[Ventura]

Best way to handle a Marshall with a MV, if it has an FX loop with a return pot, is to jump the FX loop. Run your gain about noon, the MV around 3:00 and use the return as a master. Will make your Marshall blossom.....

Post of the Year.

At least for all the plexiheads out there

 

[steve_k]

I melted the wax in the transformer of a vintage Fender ~ dime & boosting the front end big time. The wax dripped down and also messed up the speaker .... I was not using a attenuator. It happens....
As it was melting it was one the best tones I have ever got..... amazing actually. Swansong -Everyone noticed the sound / tone .... then the smoke. The power tube was actually almost white when I looked at the back as I was unplugging it from the wall....

Nice . Where were the video cameras when you need them?

 

[stephen sawall]

I melted the wax in the transformer of a vintage Fender ~ dime & boosting the front end big time. The wax dripped down and also messed up the speaker .... I was not using a attenuator. It happens....
As it was melting it was one the best tones I have ever got..... amazing actually. Swansong -Everyone noticed the sound / tone .... then the smoke. The power tube was actually almost white when I looked at the back as I was unplugging it from the wall....

Nice . Where were the video cameras when you need them?

I would be more interested in a audio recording ....