eSGEe
Ferengi Ambassador of Trade
High Voltages After Headfirst Origin 50 Mod
- Thread starter Inspector #20
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Hey! I’ve got something like that! I’m gonna be honest here….I have not biased it yet. I’m still struggling with the scope vs meter decision.
(Edit: honestly…always been a meter guy…although I do have a tone generator and a couple of scopes)
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Thanks for the heads up!make sure to change the blinker fluid and rotate the wiper blades
eSGEe
Ferengi Ambassador of Trade
I will say that I like the fact the pedals I posted above have TONS of effects in them --
and you can use them only as a full pedal board all in one
or you can turn on the models/sims .... but -- you can get a whole rack of pedals (I think the AMpero has around 242 effects
the Line 6 has another 100+
thats a HELL of a lot of pedals ........I think @RVA had around that many before he got the Kemper
lol
and you can use them only as a full pedal board all in one
or you can turn on the models/sims .... but -- you can get a whole rack of pedals (I think the AMpero has around 242 effects
the Line 6 has another 100+
thats a HELL of a lot of pedals ........I think @RVA had around that many before he got the Kemper
lol
Amp Mad Scientist
Ambassador of Heresy
OK, is there a discount for 3?
syscokid
Ambassador of War & Peace
Well, Hell! Here's my sort-of experience with biasing with an oscilloscope:Hey! I’ve got something like that! I’m gonna be honest here….I have not biased it yet. I’m still struggling with the scope vs meter decision.
(Edit: honestly…always been a meter guy…although I do have a tone generator and a couple of scopes)
Years ago, and before I got into servicing and modding my own amps, I used to own a Carvin Legacy that I bought used through Ebay. Less than two weeks later, the amp lost volume and sounded terrible. Brought the amp to a well known and local electronic repair technician. He found worn-out power tubes and a couple cold solder joints. The tech made a point of telling me that he set the bias properly using his oscilloscope, and also mentioned that the Carvin factory sets the bias on these amps very cold. Three months later the amp sounded noticeably duller and the power tubes looked very toasty. By this time I had already started to research & learn how to bias amps. One method was the meter with a bias probe tube socket adapter. When I checked the bias of the amp, every power tube was reading over 50mA's... That's over 95% dissipation!!!!!!!!!!! So yeah: Don't need or want an oscilloscope...
Maybe I will try doing my first bias with a scope…on the Kemper….what could go wrong…Well, Hell! Here's my sort-of experience with biasing with an oscilloscope:
Years ago, and before I got into servicing and modding my own amps, I used to own a Carvin Legacy that I bought used through Ebay. Less than two weeks later, the amp lost volume and sounded terrible. Brought the amp to a well known and local electronic repair technician. He found worn-out power tubes and a couple cold solder joints. The tech made a point of telling me that he set the bias properly using his oscilloscope, and also mentioned that the Carvin factory sets the bias on these amps very cold. Three months later the amp sounded noticeably duller and the power tubes looked very toasty. By this time I had already started to research & learn how to bias amps. One method was the meter with a bias probe tube socket adapter. When I checked the bias of the amp, every power tube was reading over 50mA's... That's over 95% dissipation!!!!!!!!!!! So yeah: Don't need or want an oscilloscope...
One method was the meter with a bias probe tube socket adapter. When I checked the bias of the amp, every power tube was reading over 50mA's... That's over 95% dissipation!!!!!!!!!!! So yeah: Don't need or want an oscilloscope...
Greg, I bought a pair of these to use a few months ago. Have only used them once so far on the DSL40.
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OP
Good information!!!!
OP
@old rocker - Question...does your transformer hum continue with amp switched on??? A very low frequency hum...
I’ve been quite happy with my experience with my set of those for the last 20+ years. Really. Not kidding. Not even a little bit.
syscokid
Ambassador of War & Peace
Yup, those bias-checking socket adapters, a meter, and the online bias calculators that are available for all, make it cheap and easy.
And now, here's a sad story...
I trusted this little F'r for many years and it is the coolest gadget for biasing I've ever come across. But one of the socket probes have become untrustworthy, showing false mA readings. Compu-Bias no longer exists. I would have gladly bought a new set of socket/probes.
Looks like I'm going to have to get some new bias socket adapters like Don O's and change my routine a bit.
Amp Mad Scientist
Ambassador of Heresy
Well, Hell! Here's my sort-of experience with biasing with an oscilloscope:
Years ago, and before I got into servicing and modding my own amps, I used to own a Carvin Legacy that I bought used through Ebay. Less than two weeks later, the amp lost volume and sounded terrible. Brought the amp to a well known and local electronic repair technician. He found worn-out power tubes and a couple cold solder joints. The tech made a point of telling me that he set the bias properly using his oscilloscope, and also mentioned that the Carvin factory sets the bias on these amps very cold. Three months later the amp sounded noticeably duller and the power tubes looked very toasty. By this time I had already started to research & learn how to bias amps. One method was the meter with a bias probe tube socket adapter. When I checked the bias of the amp, every power tube was reading over 50mA's... That's over 95% dissipation!!!!!!!!!!! So yeah: Don't need or want an oscilloscope...
Amp Mad Scientist
Ambassador of Heresy
Was this techs name Cheewee?Well, Hell! Here's my sort-of experience with biasing with an oscilloscope:
Years ago, and before I got into servicing and modding my own amps, I used to own a Carvin Legacy that I bought used through Ebay. Less than two weeks later, the amp lost volume and sounded terrible. Brought the amp to a well known and local electronic repair technician. He found worn-out power tubes and a couple cold solder joints. The tech made a point of telling me that he set the bias properly using his oscilloscope, and also mentioned that the Carvin factory sets the bias on these amps very cold. Three months later the amp sounded noticeably duller and the power tubes looked very toasty. By this time I had already started to research & learn how to bias amps. One method was the meter with a bias probe tube socket adapter. When I checked the bias of the amp, every power tube was reading over 50mA's... That's over 95% dissipation!!!!!!!!!!! So yeah: Don't need or want an oscilloscope...
Why do you think Mike Soldano uses a scope to bias?
I thought you liked Soldano.
Now you think Soldano is an idiot, because he uses a scope?
Just because one tech doesn't know how to bias an amp...
that doesn't mean that biasing with a scope is all wrong.
It works.
When you learn how to use a scope, it will increase your skill set. By quite a lot.
One of the most valuable tools you can use.
Now I will confirm that Cheewee is a moronic hack....that's a given.
But what you are telling us, doesn't add up to a factual conclusion.
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Amp Mad Scientist
Ambassador of Heresy
Just for all of you,
we have a local "tech" named Cheewee.
He seems to destroy everything he works on.
we have a local "tech" named Cheewee.
He seems to destroy everything he works on.
syscokid
Ambassador of War & Peace
Yes sir...Was this techs name Cheewee?
Not at all. Mike Soldano is an amp God. But he also knows his own amps. I have confidence that Mike Soldano will know when to use an O-scope or when to use alternative choices. Ivan H's rebuttal on relying on O-scopes is not the first time I've heard of this. If I had the money, space, and knowledge, I would love to have an O-scope.
Nah, Cheewee is cool. He's helped me out very succesfully over the years. I'm sure he knows how to use a scope. But this might be an example where he adjusted the bias with a scope till he saw a smooth wave form, and then said "I'm done". Probably didn't notice the voltages for the bias, or recognized them as being way under biased.
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Amp Mad Scientist
Ambassador of Heresy
So, it was Cheewee who biased your amp wrong?Yes sir...
Not at all. Mike Soldano is an amp God. But he also knows his own amps. I have confidence that Mike Soldano will know when to use an O-scope or when to use alternative choices. Ivan H's rebuttal on relying on O-scopes is not the first time I've heard of this. If I had the money, space, and knowledge, I would love to have an O-scope.
Nah, Cheewee is cool. He's helped me out very succesfully over the years. I'm sure he knows how to use a scope. But this might be an example where he adjusted the bias with a scope till he saw a smooth wave form, and then said "I'm done". Probably didn't notice the voltages for the bias, or recognized them as being way under biased.
????
Or who was it?
It wasn't me I know that much.