12AU7 in V1 of Hot Rod Deluxe III

[Little Pigbacon]

So I’ve been reading about how a lower-gain tube in V1 can change the travel of the volume knob on a Hot Rod Deluxe III. I’m just gullible enough to try this. Has anyone else here done it? I see a tube order in my future.

 

[justFred]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Worked as advertised in V2 for my hot rod Deville. Huge improvement in getting smooth volume increase vs. the abrupt jump it had between 1 and 2.

 

[Little Pigbacon]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Being in V2, did it do anything for the gain channel?

 

[Esseff]

Re: 12AU7 in V1 of Hot Rod Deluxe III

My experience in experimenting with lower gain tubes in my HRD was not very fruitful. Many ppl recommend it but I found it ruined the sound of the amp. Nobody seems to mention that.

In the end I just did a whole lot of mods including the Master Vol 250k audio taper mod, which fixes the problem properly. I know it's a bit more complicated than a tube swap but be wary of ppl telling you it is a great solution.

 

[johnthomas]

Re: 12AU7 in V1 of Hot Rod Deluxe III

So I’ve been reading about how a lower-gain tube in V1 can change the travel of the volume knob on a Hot Rod Deluxe III. I’m just gullible enough to try this. Has anyone else here done it? I see a tube order in my future.

I am trying a 5771 myself, then a 12at7, then a 12au7. The JAN-GE 5771 or even JAN-GE 12ax7s are topnotch NOS tubes for not huge prices...like $59
Do you presently use the Normal gain input or the 2nd (lower gain) input on your Hot Rod? IMHO this can tell you a lot about how you will like lower gain for the overall amp response. hint- sounds just as good to me

Sent from my SM-G920V using Tapatalk

 

[Boogie Bill]

Re: 12AU7 in V1 of Hot Rod Deluxe III

My experience with a lower-gain tube is using a 12AU7 in my Real Tube 901 overdrive pedal. Good move; it gave the pedal more range of lower gain tones, yet it still sings with the GAIN above 1:00.

You can also use a 12AT7, or a 12AY7.

Good luck.

Bill

 

[Little Pigbacon]

Re: 12AU7 in V1 of Hot Rod Deluxe III

I’m going to put a matched octet of 6550’s in V1.

 

[Little Pigbacon]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Any brand recommendations? I’m stopping by a couple of shops tomorrow, and if I’m really lucky they might have some.

 

[beaubrummels]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Lower gain tube in V1 gives more headroom to just about any tube amp. I don't have a HRD, but I've done this in a number of other amps I have. Should work fine and be a very satisfying experience. Telefunken NOS would be my first recommendation. TAD STR would be my second. Ruby, Groove Tubes or JJ would be my third.

 

[Little Pigbacon]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Well, for 12AU7’s I found a JJ (Slovak Republic), and a new-production Mullard, which is a New Sensor Brand, made in Russia. So I feel that Eastern Europe is well represented.

View attachment 87528

 

[FuseG4]

Re: 12AU7 in V1 of Hot Rod Deluxe III

Interested in the results, 12au7 is pretty low gain factor, will it change the balance of harmonics much?

 

[Chickenwings]

Re: 12AU7 in V1 of Hot Rod Deluxe III

a lot of tweed amps use a 12ay7 (deluzes, bassmans etc) in v1. 12ax7s work fine too but i prefer the 12ay7 due to the slower onset of distortion and a more tuneable sweep. I think they would suit an HRD too for the same reasons.

 

[Rick330man]

Re: 12AU7 in V1 of Hot Rod Deluxe III

I had two of the last American made HRDs, but sold one to a good friend about 2 years ago. We tweaked the tubes so that he got an EH 12AY7 in V1, a JJ ECC83S in V2 and a JAN Philips 12AT7 in V3. He loves this set up and feels it gives him the sweep he needs for cleans while still allowing for some on board drive when he wants it.

In my HRD, I kept NOS 5751s in V1 and V3 with a JJ ECC83S in V2.

A 12AU7 takes away too much.

 

[Tone Meister]

Re: 12AU7 in V1 of Hot Rod Deluxe III

I’m going to put a matched octet of 6550’s in V1.

You stole my mod, you stole my mod!! I was doing this mod to the HRDIII long before the Vietnam war, having written extensive blogs on the subject when Al was still in college inventing the internet.

Thief! :cop: