VHT pitbull fifty st g-5034-l original tube layout

General
1

Hi!
I’ve had a VHT Pitbull fifty st G-5034-L head and cab since new (1998?), and had it serviced a few times, but just wondering what the original tubes were it originally came with?

And also layout and order?

I’ve found some conflicting info between models, especially for the phase inverter and reverb driver.

Some info suggests ef86 in the mix?

Any info you have would be much appreciated.
Thanks!

2

Welcome to the forum!

If you can provide the serial number, we can get you the correct tube chart.

But for now, V1 was usually a Sovtek 12AX7WB, and all other 12AX7s were Shuguang, which coincidentally are available again now, albeit with a likely substantial price increase :enraged_face:

The power tubes were Sovtek at the time. Later switched to JJ.
Any decent 5AR4 will do.
Reverb driver for 1998 would have been EL84, but could have been modified to accept EF86. Would need to photo of the inside to determine that.

Dave

3

Thanks David,
Much appreciated.
The serial is (L) CK990158

4

That’s a 1999 model so right on the cusp. It could have been EL84, but could have been modified to accept EF86. Would need to photo of the inside to determine that.

FiftyTwelve Functions.pdf (54.9 KB)
5034 series.pdf (7.2 KB)

5

Photo of the tube section or inside the chassis?

6

Inside the chassis with good light and hi res.

7

Hi David,
I got some info from the boards which might help, and took some very average pics before you had sent your last message.

preamp board REV 4.1
Power board REV 2
Power supply board REV 2 1997

Dated to early March 1999

I will take some better pics and post them tomorrow.

8

IMG_6351
IMG_63514032×3024 3.3 MB

9

IMG_6352
IMG_63524032×3024 3.22 MB

10

IMG_6353
IMG_63534032×3024 2.86 MB

11

IMG_6354
IMG_63544032×3024 2.68 MB

12

IMG_6355
IMG_63554032×3024 2.38 MB

13

Hi
Just seeing if these pics and the board details give you more of an idea about what tubes this model used?

14

@ankledent are you aware that capacitor CS6 on the power supply board (the tan one) is blown and I’m assuming should be replaced?

15

Hi @choalla
Thanks! Wow I was looking straight at it and didn’t even clock it!!
I was focusing on the tubes that have blown and working that out.

16

@DavidPhelge
Apart from the blown cap that was spotted.
Can you tell what tubes would have been in this model?