Opinions needed on this mod and components types

[divolt]

Hi...
After studying the D type amp for about 3 weeks... learning things.. catching opinions... and have make download almost all files from the forum, i'found here by a poster that i don't remember the nick.. a modded #124 schematic.. and then make another mod on this schematic... now it haves a Deep, Mid, Bright and Rock/Jazz switches..

I don't want to make a clone of the look of D amp.. I only want the sound and if possible have more features than the original..

I wait opinions about this too:
I thinking too to use all Metal Film resistor only exceptions from plate resistors of phase inverter and power tubes that i'm thinking to put CC..
About the capacitors... i'm thinking to put in the preamp section all Xicon MPP and Silver Mica to the bright switches (and other caps that controls the high frequencies) and the original Orange drops on the power amp..

so.. my question about this schematic and to all gurus in this forum is if my mod is correct.. if it works..

[Bob-I]

I wait opinions about this too:
I thinking too to use all Metal Film resistor only exceptions from plate resistors of phase inverter and power tubes that i'm thinking to put CC..

I perfer Carbon Film 1 Watt everywhere except the plate load on V1 and V2. On these I use metal film RN65's.

About the capacitors... i'm thinking to put in the preamp section all Xicon MPP and Silver Mica to the bright switches (and other caps that controls the high frequencies) and the original Orange drops on the power amp..

First off, Orange Drop is just the coating, there are many varieties of OD caps. Most folks perfer the 6PS series of ODs but I've used the Xicon MPPs and like the sound a lot. I'd stay away from the very common 715 series of ODs as I've found them harsh.

Silver Mica may be ok, there are examples of Dumbles out there with SM caps, but in general ceramic are used. I prefer ceramic in Dumbles, you might want to experiment.

so.. my question about this schematic and to all gurus in this forum is if my mod is correct.. if it works..

I'll look later.

[divolt]

well... i've working on this... and have an update to my project.. I didn't draw anything.. only taken existing schematics is this forum...

The changes are:

- The poweramp is from original #124 schematic.

- The D-lator comes from the "D-lite convertible EL84/6v6" from schorsch (very good idea the "convertible" thing... i have spares, and after maybe i go for a TW convertible ) i need help with the voltages and the serie/parallel thing (resistor and cap value).. because i've taked the idea from kleinmulator on this one.

- The Reverb comes from the Allen schematic. What reverb trafo to use on this?? and the exact location... it's better in the Fxloop or conect after the Fxloop??? and anyone have a single tube reverb schematic?

- The Cabsim is from Marshall... need to be tweaked to sound like a TL806..

- The tonestack that i have allready talked about. i'm gonna pull off the relay mid switch.

- Added a switch choke/resistor.. do i have only switch that when the amp is on standby?

It's not the better looking schematic... but it's been changed with windows paint.. only "copy/paste thing"

EDIT: Added poweramp power off (to use in preamp mode with the cabsim or not) it shut down the power section (and heaters.. not drawn this but also have to do this)

[divolt]

hum... ok...

does anyone have at least a 1 tube reverb schematic who can share it with me? (i can't find one schematic for 1 tube only on google)

for the rest i'm finding the anwsers for myself...

[bluesfendermanblues]

hum... ok...

does anyone have at least a 1 tube reverb schematic who can share it with me? (i can't find one schematic for 1 tube only on google)

for the rest i'm finding the anwsers for myself...

You know the Dumble amps might look pretty simple - and they are - and they are not. Getting the goods from the amps can take some tweaking time and you must allow the amp time to burn in and 'settle in'.... could easily take a month.

Maybee, you are trying to invent the wheel a little bit with your design ideas.

My advise would be to build the amp as close to the original as you possible can and NOT change a single bit, before you are familar with the amp and its tone.

[Structo]

This is true.

Start with a baseline amp.
Unless you are very familiar with these amps you won't know where to begin if something is off.

So build it as the layout, schematics show, then tweak to taste after break in.

Something that was told to me but I ignored as I thought I was smart, is to make one change at a time, then give it a good listen by playing the amp several days or at least put some hours on it to give it a fair listen.
Then decide if it is going in the direction you want.

If you make a bunch of changes and it sounds like crap, you won't be entirely clear which mod or tweak is responsible for it.

If I were you I would make a folder of notes taken from this forum listing the various things people here have tried and seem to work, such as bypass cap values, plate load values, coupling cap values, etc.
So you will have an idea about what to change if you don't like a particular aspect of your tone.

Also, not sure if you are a gigging guitarist or a bedroom player, but there is a big difference in the character and tone of an amp when played at gigging volume vs. lower bedroom levels or even louder bedroom level.

The tubes start breathing at say, 90 db and will makes things apparent that lower volume playing won't show.

Also speakers play a huge role in how this topology sounds.
A lot of guys like the Celestion 12-65's while others including me like the EVM 12L speakers.
Eminence Red, White and Blues also gets honorable mention.

So just take it nice and slow and have fun with it.
You will have a pretty large investment into a build like this so build it wisely and it will pay off.
They are great amps that can cover a lot of ground, not just the Ford or Carlton tones.

[Structo]

I see you have the Dumbleator included in your schematic.
I realize there may be a couple guys that have built in this loop but it will really start getting cramped in a chassis, especially a 100 w chassis to include that inside.
Plus you want to include a reverb?
That's 9 or 10 tubes depending which way you go on the reverb.

Most build it in a rack mount chassis which isn't really necessary but traditional.
You could build it in a smaller box but like I said most build it as a separate piece of gear.

[BobW]

This is true.

Start with a baseline amp.
Unless you are very familiar with these amps you won't know where to begin if something is off.

So build it as the layout, schematics show, then tweak to taste after break in.

Something that was told to me but I ignored as I thought I was smart, is to make one change at a time, then give it a good listen by playing the amp several days or at least put some hours on it to give it a fair listen.
Then decide if it is going in the direction you want.

If you make a bunch of changes and it sounds like crap, you won't be entirely clear which mod or tweak is responsible for it.

If I were you I would make a folder of notes taken from this forum listing the various things people here have tried and seem to work, such as bypass cap values, plate load values, coupling cap values, etc.
So you will have an idea about what to change if you don't like a particular aspect of your tone.

Also, not sure if you are a gigging guitarist or a bedroom player, but there is a big difference in the character and tone of an amp when played at gigging volume vs. lower bedroom levels or even louder bedroom level.

The tubes start breathing at say, 90 db and will makes things apparent that lower volume playing won't show.

Also speakers play a huge role in how this topology sounds.
A lot of guys like the Celestion 12-65's while others including me like the EVM 12L speakers.
Eminence Red, White and Blues also gets honorable mention.

So just take it nice and slow and have fun with it.
You will have a pretty large investment into a build like this so build it wisely and it will pay off.
They are great amps that can cover a lot of ground, not just the Ford or Carlton tones.

I agree, This is great advice. Keeping a journal over the years has helped me not only keep track of the tweaks on my #124 and other amps, but also details any and all amp repairs.
FWIW, my journal and pic archive helped prove to a customer that issues with his amp, were due to another repair shop's "work" not mine. After the journal was shown to him, he then paid me to uninstall the other repair shops "work". It's also interesting to see what has changed over the years when an amp returns to my shop.

[divolt]

I understand what you're telling... but the schematics are stock #124.. stock D-lator.. Stock reverb from Allen amp... all stock values for start.. after that making the mods that i think to go right.. it's not an amp to build in one week...

About the chassis.. i know it.. i'm gonna make one custom... bigger!!

I'm not intended to create a clone.. only the inside counts for me.. i know, i'm a little crazy about the ideas.. but.. that's the way i am..

Great tip that you gave me.. taking the notes!!.... i'm gonna do that!

Thanks for the anwsers..

[Tonegeek]

I'm not intended to create a clone.. only the inside counts for me.. i know, i'm a little crazy about the ideas.. but.. that's the way i am..

You sound like me a couple of years back! Keep in mind this is a Dumble forum. If you want to get the D sound then this is the place, but every substitution you make to the tried and true will have to be revisited if your amp does not sound right once you fire it up. Read my early posts. I have been there. There is more than one way to skin a cat, as they say, but the advice you are getting now is just to keep you from getting frustrated down the road if things don't turn out as planned. Regarless, you can expect lots of help here whether you build it your way or the suggested way.

good luck....