Fender Blues Deluxe with no distornion and overdrive channel...channel switches fine

[bsco]

Good evening...I have this amp in for repair....the complaint.......when using the overdrive channel, the amp does not distort...it will however switch to the overdrive channel and the sound is there.......it's just not distorted or should I say, overdriven.........I checked the usual....tubes, pots, etc...the tone stack works fine in both clean and overdrive modes.....drive and master volumes also work fine....the amp just doesn't distort.....any ideas?????
Cheers

[Randall]

Have you looked at the relays, RY1 and RY2? You say it will switch to the drive channel, how do you know this? Is it possible the LED is switching, but not the channel itself?

[bsco]

Have you looked at the relays, RY1 and RY2? You say it will switch to the drive channel, how do you know this? Is it possible the LED is switching, but not the channel itself?

Thanks for the reply.....But if the relays were not switching, then the drive and master volume controls would not be functioning?? and the clean channel volume would still be working...I'll check them out just to make sure....
Cheers

[alexradium]

did you change tubes?

[bsco]

did you change tubes?

Yes sir....that was the very first thing I tried.......funny how the amp switches to overdrive and the drive channel works and is loud like it should be but it does not produce any overdrive....just a louder clean volume......I have to run some errands this morning...when I get back I am going to check a few things out.....thanks for the reply......
Cheers.....

[alexradium]

looking at the schematic,the whole drive thing is controlled by the 2 relays,they are there just to attenuate the signal,most probably they don't work because the coil is gone or the driving circuit is faulty.

[Jazz P Bass]

The Blues Deluxe does not distort on the Drive Channel.

It's louder, yes, but there is not a gain stage that you are switching in and out.

As Alex stated, the Clean & the Drive channel is a matter of attenuating the signal at V2 B differently. (and removing the Clean volume control)

One thing to keep in mind is the fact that if both inputs are used, you get the 'Low' signal.
So maybe you should check that the jacks are closing properly when nothing is plugged in.

[bsco]

Thanks for the reply Jazz.......so basically, from what you are saying, this amp does not distort....the drive channel is basically only a volume boost.....and defeats the clean volume control......which it does.....so.....maybe......just maybe the amp is fine..........I have to run into the store tomorrow.....I think they have a couple of these in there...I will have to try one out and compare......I will check those two jacks just to be sure.....and I am going to check to see when this amp was purchased...it could be the fact that the owner bought this very recently thinking it distorts in drive mode.....I'll let you know what I find out......
Cheers

[Jazz P Bass]

There is a small gain boost when the Clean volume control is disconnected.

Key word: Small.

[bsco]

Hi Jazz..Sorry for the delay....I tried the amp in that is on the sales floor in the store.......It has slightly more dirt....but not distorted by any means....I tried replacing both V1 and V2 tubes after just to see.....it did make some difference......but nothing drastic.....it does have a bit more dirt in the meantime so I finished it up and returned it.....Thanks for the help.....
Cheers

[1ampman]

Were the 12ax7s you replaced stamped with WC a higher gain 12ax7? Sovtech has 3 levels of gain in their 12ax7 line up. WA lowest gain,WB & WC more gain.

[bsco]

Were the 12ax7s you replaced stamped with WC a higher gain 12ax7? Sovtech has 3 levels of gain in their 12ax7 line up. WA lowest gain,WB & WC more gain.

Thank you for your reply....That I do not know...however, I will make a note of the info you just gave me and keep it for future reference.....Thank you very much....
Cheers