Cathode Follower in BA/Maverick?

[Nathan]

Hey guys,

I have a small question re. cathode follower seen in the Blue Angel V1b but also Maverick V1b.

I have been looking at the schematics readily available online.

It appears that the Maverick has the cathode follower switchable with the bright/fat cap, but the BA seems to have the cap only (ie. cathode follower stays on all the time).

I don't own a Maverick, but my Blue Angels have a simple SPST switch. I am guessing the Maverick would require a DPDT switch?

Can anybody confirm my assumptions?

Thanks!

 

[Nathan]

Bump for posterity?

Would a 12DW7 be better in V1 for the Blue Angel/Maverick?

What about that switch?

 

[tbonesullivan]

Bump for posterity?

Would a 12DW7 be better in V1 for the Blue Angel/Maverick?

What about that switch?

You can see it in the upper right. Definitely has a lot of wires going to it. I have a used old stock something in that position, so it won't fry like the recent production Russian spiral filament tubes.

 

[austin sonar guru]

I don't know if this will provide any insight but here goes:

As you asked about preamp tubes in your second post I thought I'd provide this.

This is what I use in my BA for the last two years or so. I've had the amp 27 years. Using a lower gain triode in V2 is probably the most significant thing. 12AX7 is too hot.

V1 - preamp first stage - NOS RCA 7025 short plate
V2 - preamp second stage - NOS RCA 5751 black plate
V3 - reverb input driver (both stages) - NOS Mullard Blackburn ECC-81 (12AT7)
V4 - a stage - parallel effects loop/b stage - Reverb output driver - 12AX7 Gold Lion (not NOS)
V5 - Phase inverter - 12AX7 Gold Lion

Note: You can save some money and use a 12AT7 in V2 which will reduce hum quite a bit. Five 12AX7's are not optimal in this amp for many reasons which I won't elaborate on here. I've only changed power tubes twice in the history of the amp, and not due to failure.

No hum. There are only two mods I've ever made to the amp. Mine's a 2X10.

1 - Replaced stock speakers with 2 Celestion golds (16 ohms)

2 - replaced a 1 watt 100 ohm resistor with a 2 watt version, which killed the "pop" that I was experiencing when using the bright/fat switch. The original was fried. The resistor is in the same area of the BA circuit board as the fan - on the lower left hand side when viewed from the back. It's located in between two diodes next to the 180V filter caps (preamp power supply). When it's bad, there's too much potential on the preamp, so when you switch it "pops". The amp still works, but it's irritating. Only design flaw imho in the amplifier. The 1 watt original is just spec'd too low.

Probably way too much info - but hope it helps.