Search found 96 matches

by joe6v6
Wed Jul 25, 2018 3:11 pm
Forum: Dumble Discussion
Topic: JM Signature hum with neg feedback on (pics added)
Replies: 8
Views: 711

Re: JM Signature hum with neg feedback on (pics added)

I've that exact thing happen. Because there was no "squeal" as one normally would experience, it took some time to figure it out. Same here, no squeal just loud humm. I dis connected the negative feed back first just to verify, switched the primaries & all was well. Glad you got it going. I Love mi...
by joe6v6
Tue Jun 26, 2018 3:40 pm
Forum: Dumble Discussion
Topic: A few ?'s re- my Wonderland build
Replies: 10
Views: 1253

Re: A few ?'s re- my Wonderland build

I added a 220k resistor on the send pot & it made a big difference in the right direction, Im thinking of changing that pot to 1 Meg. Should I do anything to the return pot? . . All the voltages are right in line with whats on the layout, I did try jumping the 10K dropping resistor to up the voltage...
by joe6v6
Tue Jun 26, 2018 3:10 am
Forum: Dumble Discussion
Topic: A few ?'s re- my Wonderland build
Replies: 10
Views: 1253

Re: A few ?'s re- my Wonderland build

Using an AT7 helped a little but not much. I want to get a good bit more out of it before I call it done. Does anyone think changing the 100k send & return pots to 250k or beyond will increase the signal to the reverb tank? I changed the 220k grid resistor on v2 to 470k & again it may have been a li...
by joe6v6
Sat Jun 23, 2018 2:20 am
Forum: Dumble Discussion
Topic: A few ?'s re- my Wonderland build
Replies: 10
Views: 1253

A few ?'s re- my Wonderland build

I have finished my Wonderland build & have built it a very nice Maple head cab which awaits its final tweaking. The amp fired right up with no real issues, after swapping the OT primaries, it didnt squeal but rapid speaker oscillation occurred, swapping the OT primaries corrected it. The amp sounds ...
by joe6v6
Sat Jun 16, 2018 2:27 am
Forum: Dumble Discussion
Topic: This one's for Bob
Replies: 17
Views: 2025

Re: This one's for Bob

Wow - Looks like a lot of planning & for thought went into this one, I just got done shoehorning a Wonderland into a 17" chassis & your build makes it seem like I had plenty of room. I can see where those cap cans would free up a lot of room but your still going to have a full house there. Cant wait...
by joe6v6
Thu May 17, 2018 3:49 am
Forum: Dumble Discussion
Topic: Wonderland with EL34's?
Replies: 5
Views: 723

Re: Wonderland with EL34's?

Thanks for the info, Once I got to looking around Ive seen where several people have built this amp with EL34s & loved it! I dont have any old pinball machines laying around but I do have enough spare parts to put one of these together without one. , I think Ill stay away from the ultra linier & jus...
by joe6v6
Wed May 09, 2018 11:18 pm
Forum: Dumble Discussion
Topic: Wonderland with EL34's?
Replies: 5
Views: 723

Wonderland with EL34's?

I have some decent doner Iron from a Seymor Duncan Convertiable amp that ran 4 EL34's. I was wanting to get opinions on how best to use it in a JM Wonderland amp with reverb. I have attached both the Wonderland schematic and the SD schematic. Would I be best off using EL34's? I dont see the primary ...
by joe6v6
Fri May 04, 2018 8:15 pm
Forum: Dumble Discussion
Topic: 102 Up & Running
Replies: 4
Views: 641

Re: 102 Up & Running

The power trans is a P-T290DX its 325-325 @ 200ma, I used the 5v tap for the relays. . The Output is a Magnetic Components Classic Tone 40-18001. I already had the 4ohm one but I got this because In a head I wanted to have the option of diffrent cabs. Tx - Joe
by joe6v6
Fri May 04, 2018 4:29 am
Forum: Dumble Discussion
Topic: 102 Up & Running
Replies: 4
Views: 641

102 Up & Running

The 2 Tube 102 Ive been working on fired right up, bias was set all the voltages were well with in range. I pluged it into a 2x12 cab & it was immediately apparent that something was not right. All the controls & the boost & OD worked just fine but it just sounded bad with awful overtones and distor...
by joe6v6
Sun Apr 29, 2018 1:51 am
Forum: Dumble Discussion
Topic: Which 50 watt Dumble should I build ?
Replies: 15
Views: 3101

Re: Which 50 watt Dumble should I build ?

The LNFB switch on this layout- seems to just ground the negative feedback circuit on V1. Is this a good way to do it? Would it be better to put a switch that diconnects it? And lastly what affect does it have on the tone, sound, feel of the amp? . . Sorry , I could not finda a schematic that shows ...
by joe6v6
Mon Apr 23, 2018 5:24 pm
Forum: Dumble Discussion
Topic: Eliminate effects loop ?
Replies: 12
Views: 1567

Re: Eliminate effects loop ?

A friend of mine said he noticed a significant decrease in volume when pluging some pedales into the unbufferd loop on another amp I built, Is this normal with the unbufferd loop & would the dumbleator correct this? tx - Joe
by joe6v6
Mon Apr 23, 2018 3:38 am
Forum: Dumble Discussion
Topic: Eliminate effects loop ?
Replies: 12
Views: 1567

Re: Eliminate effects loop ?

So if nothing else I should include the unbuffered loop so I can plug a buffered loop into it. How hard is it to shoehorn a D-Lator into the amp? I remember reading about amps with a "built in" D-Lator. Any benifit to having it built in? Can someone point me to the most popular version of the D-lato...
by joe6v6
Sun Apr 22, 2018 3:27 pm
Forum: Dumble Discussion
Topic: Eliminate effects loop ?
Replies: 12
Views: 1567

Eliminate effects loop ?

I am working on a #102 and I want to eliminate the effects loop, is it as simple as attaching the wiper of the master volume to the .02 cap that goes to the grid of v3 or is there something else to consider?
by joe6v6
Thu Apr 12, 2018 12:06 pm
Forum: Dumble Discussion
Topic: Which 50 watt Dumble should I build ?
Replies: 15
Views: 3101

Re: Which 50 watt Dumble should I build ?

Ive already got the transformers im going to use for the 50W so maybe the 100 will be next time. For the most part I just wanted to confirm using the 102 layout & schematic as they are(-2 tubes) My output trans only has a 4ohm tap, its been laying there for a while wating to be used. . Thanks : Joe
by joe6v6
Thu Apr 12, 2018 2:16 am
Forum: Dumble Discussion
Topic: Which 50 watt Dumble should I build ?
Replies: 15
Views: 3101

Re: Which 50 watt Dumble should I build ?

I am going to build the Ford #102 with 2 x 6L6 - are there any values on the layout or schematic that should change going from 4 power tubes to 2? Or just go with it the way it is. Im actualy pretty excited now that ive settled on what amp im building, all these variations remind me of picking out a...