HI Res AB 165 layout

[angelodp]

Would any kind soul possibly have a clear hi res AB 165 layout ( and a schematic if possible ). I have searched and searched but they are all lacking in sufficient detail to make out many values.

Best

[M Fowler]

On the bottom of this mojotone kit page is the layouts and schematics

http://www.mojotone.com/amp-parts/amp-k ... KR8StLF-So

[martin manning]

Clear AB165 schematic and layout are here: http://vintagefenderamprepair.com/schematics/

Cheers!

[angelodp]

Thanks guys…. Happy New year.

On this Bassman, it has been messed with a bit and now set up for EL34, s. I have not fired it up yet… I'll bring it up slowly tomorrow. I think its a 64 and in pretty good shape. Its a head type. I don't think this amp has been on in quite a while, so I'll do a bulb limiter test with out tubes and work my way up to sound. It has some interesting tubes. !2au7 in V1, 12at7 in V4, V2&V3 no discernible info on them. I suppose I should return to stock and see whats what. Any recommends for procedures?

Cheers Ange

[angelodp]

Well, I did the bulb limiter, all was well. I just went the compliment of tubes that it had going and sure does sound pretty good. I'll do some voltage readings and try the usual tubes tomorrow. One thing… when I did the bulb limiter with tubes, it lit up with power and then died back to a dull glow, then with standby flipped it did glow slightly more?? No smoke and sounds good so I suppose all is well. More soon.

Have great Year Martin and Mark… you guys rock.

Ange

[M Fowler]

Glad to help out.

[martin manning]

Thanks Ange, same to you.

One thing… when I did the bulb limiter with tubes, it lit up with power and then died back to a dull glow, then with standby flipped it did glow slightly more??

That's normal. With power on you get the cap charging surge and filament current glow; then when you go off standby you get another cap charge surge and the addition of the tube idle current to the glow.

[Stevem]

Those 34s pull near a full amp more heater current than a 6l6 so I would check your heater voltage and if you find you have less than 6.1 volts than two things are going on, 1) your not getting good enough cathode heating and tube performance,and 2, you best save up for a new PT because your will slowly burn up!

[angelodp]

Ok will do. On that heater voltage, would that be done with the bulb limiter in place or without?

Ange

[martin manning]

No limiter. If you run a pair of EL34 at 1.6A each filament vs. 6L6 at 0.9A each, that means you are asking for an additional 1.4A from the PT. If you are going back to 6L6's, then no worries.

[Structo]

I have a few Fender schematics/ layouts that are drawn clearer.
I think I got them from the Groove Tube book.

[angelodp]

Hey Tom, bottom one is stellar, thank my man. Have a great year Tom.

Best Ange