12AU7 As Phase Inverter or Cathode Follower in DSL40C???

[Inspector #20]

 

[Cadorman]

I think I have a couple of new 12AU7's but I am out of 5751's. I am thinking about setting Mitch's amp up with ECC83 in V1, a 12AU7 in V2 and ECC83's in V3 and V4, because I have those in my hand right now. The 12Au7 in v2 will roll off some gain and allow use of 'Lead 2' on the DSL40C....

Mitch sent me his address. I'm sending everything in my picture to him for you guys to play with.

 

[Mitch Pearrow SJMP]

Mitch sent me his address. I'm sending everything in my picture to him for you guys to play with.

Thanks again brother, I am sure I will find a great home for them!!

 

[ChasFred]

Preamp Tube Gain Factors And Substitution Chart – 300Guitars.com

excellent chart. I have it bookmarked. Thanks!

 

[Inspector #20]

Mitch sent me his address. I'm sending everything in my picture to him for you guys to play with.

Thank you, Sir....

I am giving Mitch a nice speaker that will go with those tubes...

I'm thinking of:

V1: 12AT7
V2: 12AU7
V3: ECC83
V4: 5751

Here's the spec sheet on the 'production sample' Eminence speaker i have on hand:

 

[Jethro Rocker]

I have some old AU7s from a dead Hammond organ. I believe they are Amperex or GE.

 

[Amp Mad Scientist]

Can you help me better understand that??? I do not recall seeing a 'gain factor' listed for any of these tubes!!!!!

The gain is expressed as: "mu." The symbol for mu may be "u"...the mu of an individual tube can vary a lot.
12AX7=high mu =100
5751 mu= 70
12AT7 mu=60
12AU7 mu=17

 

[Inspector #20]

The gain is expressed as: "mu." The symbol for mu may be "u"...the mu of an individual tube can vary a lot.
12AX7=high mu =100
5751 mu= 70
12AT7 mu=60
12AU7 mu=17

Thanks, Man!

 

[Cadorman]

Bumpety bump. Just thought I would see what I have in the ol' TSL100 and report back.

V1. JAN Sylvania 5751
V2 Sylvania 5751
V3. GE 12AX7
V4. MULLARD 12AX7

The first 3 are all vintage. The Mullard is new production. I really like this combination. No fizz at all and if I need that little something to get me over the top I can hit the front end with an overdrive.