59 Bassman LTP PTP Conversion Low output

Completed amps from Fender, Orange, Hiwatt, Vox, etc.

Moderator: VelvetGeorge

Post Reply
Maxsmart2014
New Member
Posts: 2
Joined: Fri Jun 27, 2014 7:03 pm
Just the numbers in order: 13492

59 Bassman LTP PTP Conversion Low output

Post by Maxsmart2014 » Sat Jun 28, 2014 1:28 pm

Greetings everyone,

First, I have learned so much from this forum and thank all of you for your posts. :thumbsup:

I have just completed a conversion form stock LTD to a Mojo T point to point using the stock trannies. I have a 5U4 for the rectifier and Tung sol 5881s for output tubes all the pres. are all 12ax7. I have sound and can play through the amp, however, I do not have any tone control functionality and the amp is gutless flubby and the volume knobs only increase gain and not do much volume. I have double and triple checked the wiring. Please help!
Voltages are, (Heaters are all good so I left them out)

5U4

3-9 358 Vac
2-8 461-446 dc resprctively

V5
3 445
4 460
5 -53
6 444

V4
3 444
4 460
5 -53
6 443

V3 (these look odd to me)
1 407
2 1
3 6
6 408
7 1
8 6

V2
1 195
2 0
3 1
6 354
7 195
8 192

V1
1 235
2 0
3 1.97
6 236
7 0
8 1.97

Maxsmart2014
New Member
Posts: 2
Joined: Fri Jun 27, 2014 7:03 pm
Just the numbers in order: 13492

Re: 59 Bassman LTP PTP Conversion Low output

Post by Maxsmart2014 » Mon Jun 30, 2014 5:31 pm

Turns out that a 47k resistor on the PI cathode will cause this behavior. Just in case anyone is looking for this type of thing :P Amp works Awesome now!

Here is a gut shot for anyone who is interested.
20140626_205004 copy.jpg
59 Conversion Shot
(371.74 KiB) Downloaded 503 times

Post Reply