Search found 41 matches
- Sat Dec 19, 2020 10:27 am
- Forum: Technical Discussion
- Topic: Benson Monarch
- Replies: 480
- Views: 75028
Re: Benson Monarch
Just Curious, has anyone figured out the power supply error in the monarch schematic? I'd like to try and build one of these over the holidays. I'm thinking maybe the error is the number of stages connected to each node, or maybe something specific to the reverb version? I built it basically as dra...
- Fri Dec 18, 2020 4:17 pm
- Forum: Technical Discussion
- Topic: Benson Monarch
- Replies: 480
- Views: 75028
Re: Benson Monarch
Just Curious, has anyone figured out the power supply error in the monarch schematic?
I'd like to try and build one of these over the holidays. I'm thinking maybe the error is the number of stages connected to each node, or maybe something specific to the reverb version?
I'd like to try and build one of these over the holidays. I'm thinking maybe the error is the number of stages connected to each node, or maybe something specific to the reverb version?
- Thu Dec 03, 2020 9:09 am
- Forum: Technical Discussion
- Topic: Help with eyelet board for 5e3 needed
- Replies: 19
- Views: 1659
Re: Help with eyelet board for 5e3 needed
I bend my components to make a mechanical connection when I do a new build. When replacing parts in an existing build, I don't bother trying to hook them in or anything like that as that would be a major PITA. I haven't had any issues so far!
- Wed Dec 02, 2020 9:50 pm
- Forum: Technical Discussion
- Topic: Oscillation/Squeal when touching power tube while plugged into amp
- Replies: 9
- Views: 850
Re: Oscillation/Squeal when touching power tube while plugged into amp
Lead arrangement/alignment can be very important with this kind of thing. SImply pushing them around while the problem is ocurring with a wooden chopstick can often show you exactly where the problem is. have you also checked that it isn't the instrument cable to be sure? ~Phil I have been chopstic...
- Wed Dec 02, 2020 8:27 pm
- Forum: Technical Discussion
- Topic: Oscillation/Squeal when touching power tube while plugged into amp
- Replies: 9
- Views: 850
Re: Oscillation/Squeal when touching power tube while plugged into amp
Okay so from my experience, even with the amplifier in the chassis, the closer I get the guitar to the amplifier, the higher the chance to induce hum/noise due to the guitar. This only seems to be a serious problem with single coils though, humbuckers seem to avoid it a ton better (thus the name hu...
- Wed Dec 02, 2020 5:55 pm
- Forum: Technical Discussion
- Topic: Oscillation/Squeal when touching power tube while plugged into amp
- Replies: 9
- Views: 850
Re: Oscillation/Squeal when touching power tube while plugged into amp
There’s dozens of permutations of the 5F6A circuit used in JTM45. Exactly what schematic have you used, including PT, OT and choke spec? The OT is an MM Radiospares 045RS-L, the PT is an MM P4550JT-G2M and the Choke is an MAR100C, also by MM. As for the schematic, I've gone with the vintage JTM45 s...
- Wed Dec 02, 2020 5:53 pm
- Forum: Technical Discussion
- Topic: Oscillation/Squeal when touching power tube while plugged into amp
- Replies: 9
- Views: 850
Re: Oscillation/Squeal when touching power tube while plugged into amp
Is the amp bolted down on a steel plate sitting in its cabinet to shield out what sounds to me like 120 HZ buzz that your discribining? Also are the power tubes wired pin 2 to pin 2 and 7 to pin 7? Is the wire coming off each pair of your input jacks sheiled? Thanks for the reply, it's definitely a...
- Wed Dec 02, 2020 4:43 pm
- Forum: Technical Discussion
- Topic: Oscillation/Squeal when touching power tube while plugged into amp
- Replies: 9
- Views: 850
Oscillation/Squeal when touching power tube while plugged into amp
Hi All, I'm currently working on a JTM45 build. When I up crank the bright channel volume, presence and treble and touch or get close to one of the power tubes with my hand while a guitar is plugged in, I'm getting very high pitched oscillations/squealing. This does not happen if I don't plug in a c...
- Thu Nov 26, 2020 1:58 pm
- Forum: Trainwreck Discussion
- Topic: under board wiring-Express question.
- Replies: 13
- Views: 3369
Re: under board wiring-Express question.
I only solder from the top. When I install the jumper I put just enough solder on the rim of the turret to hold the jumper in place. No solder inside at this time. It's hard to see any solder in that pic, but it's there. Once all the components leads are in the turret I partially fill the turret wi...
- Thu Nov 26, 2020 10:36 am
- Forum: Trainwreck Discussion
- Topic: under board wiring-Express question.
- Replies: 13
- Views: 3369
Re: under board wiring-Express question.
Like this... http://sluckeyamps.com/VAC15/underboard_jumper.jpg Sorry to revive this old thread, but I am just curious, when you use this method, do you solder the jumper from both sides of the turret or just the top side? I suppose you don't want to fill the turret completely with solder? At the s...
- Tue Sep 08, 2020 5:03 pm
- Forum: Fender Discussion
- Topic: Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?
- Replies: 1
- Views: 644
Re: Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?
In case anyone else ever finds themselves wondering about this, I just got the answer from Mojotone today. These transformers have a different stack made with thinner laminations that are a different material than the original. This then allows them to use a larger gauge wire with less turns, while ...
- Thu Sep 03, 2020 7:04 pm
- Forum: Fender Discussion
- Topic: Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?
- Replies: 1
- Views: 644
Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?
Hi All, I recently got a used Heyboer OT for a Deluxe Reverb. It came from a reliable guy, but the EIA/Model sticker is unfortunately gone. I've tested the ratio with my variac and it seems to have the winding correct ratio for a DR, however, the DCR measurement I'm getting with my DMM on the primar...
- Fri Apr 24, 2020 1:46 pm
- Forum: Fender Discussion
- Topic: AB165 Bassman crackle in V1 and V3 stages??
- Replies: 49
- Views: 9207
Re: AB165 Bassman crackle in V1 and V3 stages??
Sure why not give it a try. That 27k resistor used to have about 3 mA flowing through it, and now it's more like 4 mA. I think if you reduce the value by 3/4 it will get the voltages back to about the same as they were. 27 x 3/4 = 20.2, so I'd try the 22k. Did the mod, voltages went up but only a l...
- Thu Apr 23, 2020 9:01 pm
- Forum: Fender Discussion
- Topic: AB165 Bassman crackle in V1 and V3 stages??
- Replies: 49
- Views: 9207
Re: AB165 Bassman crackle in V1 and V3 stages??
Sure why not give it a try. That 27k resistor used to have about 3 mA flowing through it, and now it's more like 4 mA. I think if you reduce the value by 3/4 it will get the voltages back to about the same as they were. 27 x 3/4 = 20.2, so I'd try the 22k. Sweet, I'll be giving that a try tomorrow!...
- Thu Apr 23, 2020 6:25 pm
- Forum: Fender Discussion
- Topic: AB165 Bassman crackle in V1 and V3 stages??
- Replies: 49
- Views: 9207
Re: AB165 Bassman crackle in V1 and V3 stages??
I believe it is due to the different voltages causing DC current to flow along several paths, including through the 470k LNFB resistor, which is connected to the grid of the mixer stage. Those voltages will change with different tubes, too. Switching the supply node must be reducing the DC current ...