Thinking, planning, deciding - New direction...

[LooseChange]

Hi All,

I am considering building Dumble. I've been all over this site.
If I build, I will do it from scratch including chassis fabrication.

The HRM looks like the one to build. Here are some questions:

1. What is the dimensions of the chassis?
2. What's up with the FET input? Is it used? When?
3. Output Transformer... What do you like??
4. Does anyone use the preamp out/poweramp in for anything?
5. Players, Do you use all the foot switchable options??

Thank you!!

Dan

[odourboy]

Hi All,

I am considering building Dumble. I've been all over this site.
If I build, I will do it from scratch including chassis fabrication.

The HRM looks like the one to build. Here are some questions:

1. What is the dimensions of the chassis?
2. What's up with the FET input? Is it used? When?
3. Output Transformer... What do you like??
4. Does anyone use the preamp out/poweramp in for anything?
5. Players, Do you use all the foot switchable options??

Thank you!!

Dan

Well, I think Mr. Heisthl had the right idea in a recent post.... you 'need' a high plate non-HRM, a low plate non-HRM and regular HRM and a BM HRM.

Then the question is 50W good enough or do I need to go to 100W?

I believe the standard chassis size is 19" X 8" X 2"

The FET input is generally useless and if you're doing your own chassis, I'd skip it. If you want to remain faithful to Dr. D, you'll put it in and put some tapeover the input.

Pre-out Main-in is extremely useful. You'll likey need a buffered effects loop to go with it, but for the cose of a couple of jacks, don't skip it.

Hope that helps.

[LooseChange]

Thanks!

I have a Hammond 17x8x2 I like to use. That should work.

high plate non-HRM, a low plate non-HRM and regular HRM and a BM HRM

Please explain??

[odourboy]

Thanks!

I have a Hammond 17x8x2 I like to use. That should work.

high plate non-HRM, a low plate non-HRM and regular HRM and a BM HRM

Please explain??

I thought you said you'd been all over this site!! LOL!

HRM is the basic topology used by Dumble in his more recent amps and includes a post overdrive section internal tone stack. non-HRM is a product of the 70's and 80's and does not have the second stack. Each has it's merits and it's cheer leaders.

I think if I were doing my first over again, I'd go with a non-HRM because I think it's easier for an inexperienced builder to dial in and it's a general more forgiving amp to play through. Some popular production amps such as Fuchs came out of the non-HRM camp. That said, there are some incredible sounding amps being produced based on the HRM topology and our own Dogears has posted numerous HRM clips on ths site that are absolutely killer.

The low plate versus high plate non-HRM refers to the size of the plate resistors (and corresponding cathode resistors and caps) used in the preamp stages. Low values would be 100K used for all of V1a V1b (clean) V2a V2b (overdrive). These amps are reported to deliver really excellent tones. A design using 220K/150K/220K/150K or 220K/150K/180K/120K could be considered high plate and are reported to provide an extremely smooth overdrive.

The regular HRM (check out the ODS-101-HRM for a 'typical' design) differes from the BM HRM in the the BM uses a different tone stack (more Fender like) and a different phase inverter/presence/negative feedback arrangement (liek some Marshalls). It can deliver a glorisous tone loaded with bloom and harmonics, but it's more of a low-gain beast and some have found it tough to dial in and demanding to play.

Hope that helps. I should state that I am far less expereinced than many of the builders on this forum, so I invite others to comment (esp. if you feel I'm mistaken somewhere.)

Cheers!

[Normster]

As you're thinking, planning, and deciding...might as well add "prototyping." Use the Hammond box to build a prototype. Try a few different ideas out and at the same time, start collecting parts for your "ultimate" build. (Some of us believe there's no such thing as "the last build." )

As for fabricating your own chassis, consider getting one from Funkalicousgroove instead. By the time you factor in time, materials, sublet (faceplates), etc., it's the best bargain going.

[Bob-I]

Hi All,

I am considering building Dumble. I've been all over this site.
If I build, I will do it from scratch including chassis fabrication.

These amps are fairly heavy, the Hammond may be ok, but keep the weight in mind, it may bend.

The HRM looks like the one to build. Here are some questions:

1. What is the dimensions of the chassis?
2. What's up with the FET input? Is it used? When?
3. Output Transformer... What do you like??
4. Does anyone use the preamp out/poweramp in for anything?
5. Players, Do you use all the foot switchable options??

Thank you!!

Dan

2) I've built an amp with the FET input but I found it fairly useless. It gave a slight boost but in general added nothing to the tone.

3) For the OT, if you're going 50 watt use a Bassman type, 100 watt use a Twin Reverb type. Mercury Magnetics seems to work well as do many other. Make sure to get one with multiple impedance taps.

4) Yes, all the time. I built a Dumbleator into one of my amps, works well but the one that REALLY works is the external parallel effects loop I built in a single space rack chassis. The schem is posted somewhere here.

5) Yes, I use all the footswitch options, and then some. I added a mid boost footswitch on one of my amps and I like it, especally with a Tele or Strat.

[Luthierwnc]

There isn't just one. Even if you build the right one, you won't know it until you've built the rest. The best advice I could offer is start with the sound you want and work from there. I've liked my higher voltage (north of 450VDC) units better than the lower voltage versions.

I would just add that you should leave yourself a little extra room. These things are pretty densely populated and some of the specific components we use are considerably larger than the generic equivalent (i.e. orange drops vs 150's, RN65 resistors vs. little metal films). Keep an eye to where you are going to ground coax. Really keep an eye on where you run the relay hots.

Merry Christmas, Skip

[phsyconoodler]

Hey loose!
I build mine totally from scratch and even scratch built the reverb into it.
The size of the chassis is nowg=here near the D'Lite and was something I just did off the cuff.I spaced out a faceplate first with the controls I wanted,keeping in mind the knob clearances and built a chassis accordingly.Keep in mind room inside for relay supply boards and such and you'll be fine.Nobody says it has to be the same size as a Dumble.My first one was so small I had to mount the footswitch power supply and relay boards on the outside of the chassis!

[LooseChange]

I think I want to build the D'Lite with 6L6's. Actually, I'd like to build it like yours, with the reverb. I am definitely not the copy type. In fact I'd like to build this with the tubes up, left to right.

Question about all the stuff ON the tube sockets like the 250p and 22M... Is this really necessary to get the tone? I like to get all the parts on the board if possible.

Thanks!!

[Funkalicousgroove]

I think I want to build the D'Lite with 6L6's. Actually, I'd like to build it like yours, with the reverb. I am definitely not the copy type. In fact I'd like to build this with the tubes up, left to right.

Question about all the stuff ON the tube sockets like the 250p and 22M... Is this really necessary to get the tone? I like to get all the parts on the board if possible.

Thanks!!

Yes, it is. You are best off not re-inventing the wheel.

[LooseChange]

Okay I won't mess with it.
Is a D'Lite with 6L6's a good amp choice to get the sound we all want to hear? Or do I need to go to the next level and do the one with the extra tone stack in the OD stage?

Thanks!

[phsyconoodler]

You can get Robben Ford and Larry Carlton,Santana and many more with a D'Lite 44.
My 40 watter is kickin'!I have less plate voltage because I used Hammond Iron but nothing is lost in terms of tone.In fact it is seriously good.

[LooseChange]

Phsyc, is the 40 watt the one with reverb? Is there any differences between the 44 and the D'Lite except for powertubes?

[Structo]

The 44 comes with a dual primary OT, 4K and 6K, so you can run 6V6 or 6L6 type tubes and it comes with 6L6 tubes.
I used a DPDT switch on mine to be able to switch between windings so I don't have to transpose the impedance settings on the impedance switch.
Some D'Lite 22 builders have reported getting this OT with their kits.

[LooseChange]

No kits for me. I am a scratch builder. I'm going to build for 6L6's

But you bring up a good question: OT's
What OT is considered the best for a 44??