Manzamp!

[bluesfendermanblues]

Hi IC-racer, do you have a schematic for your new amp. Could be nice to have in the files section

[JazzGuitarGimp]

Another test fit of the components and chassis:
[IMG768]http://img.photobucket.com/albums/v670/ ... ile-19.jpg[/img]

That is one gorgeous build, IC. The juxtaposition of the "industrial strength", shiny, unibody chassis with the "artsy" visage of the board is really easy to look at.

[ic-racer]

Hi IC-racer, do you have a schematic for your new amp. Could be nice to have in the files section

I'm real close to posting it but I want to get a little farther along. I think it will be interesting to see how long after I post my schematic the commerical Manzamp clones will start to appear

In terms of DIY clones, I have every intention of posting my layout, schematic and circuit board Xerox transfer information when I'm done. Even if the one I build does not sound that fantastic off the bat, there are a lot of unknowns in the schematic, and I suspect builders here will have their own interpretations of what a Dumblized Hotrod 5f6A would be.

I suspect people would want to make the board with more eyelets than I have shown, so that more of the components can be swapped from the top if needed for tweaking it.

I also want to point out that the PC architecture of the Power Supply, PI and tone stack and most of v1 and v2 are likely to be correct. There is the possibility that he has some unique architecture in the tone stack, v1 or v2 that is both oddball and not in any other amp reviewed in detail on the forum here. Should that be the case (if someone ever posts better real Manzamp information) my opinion is it would be highly unlikely there would be a major re-design of the PC board needed.

[ic-racer]

That is one gorgeous build, IC. The juxtaposition of the "industrial strength", shiny, unibody chassis with the "artsy" visage of the board is really easy to look at.

Thanks. Even if it does not sound good, it will look cool!

[LeftyStrat]

If you're looking for a cool faceplate idea to top it off, I tell you what I've been planning for my 5f6 clone.

I've ordered the brass, but have not attempted the technique yet.

Basically you print an inverted mirror image of your design on toner transfer paper, then iron it on to the brass.

Then use a section of PVC pipe, capped at one end to make a bath of ferric chloride for the faceplate.

I have an artist friend who offered to design something sort of steampunkish, and then I planned on using one of the aging techniques (vinegar, lemon juice, etc) to give it an aged look.

I wanted something that looked like it had just stepped out of a Jules Verne novel. Maybe go with brown leather instead of tolex, complete with old steamer trunk hardware.

Of course, so far I'm at a loss for what kind of knobs would look good with brass.

The other unfortunate issue I've run into is the repro steamer trunk hardware is all brass plated instead of solid brass, so I'm not sure how it would stand up to the aging process.

[ic-racer]

As things come together I am finding very little room for the star grounds I planned (even though they did not show in the picture). Maybe he grounded on either or both the transformer mount screw and octal socket screw.

I did find Dumble examples of both of these grounds. This is an amp similar to #40 (but I don't know the exact number) that shows a ground on the octal socket mounting screw:
[IMG:615:698]http://img.photobucket.com/albums/v670/ ... round1.jpg[/img]

And here is a Dumble Special showing a ground on the power transformer mounting screw:
[IMG:620:503]http://img.photobucket.com/albums/v670/ ... round2.jpg[/img]

So, I think I will use both of those techniques for my grounds.

[bluesfendermanblues]

Hi IC-racer, do you have a schematic for your new amp. Could be nice to have in the files section

I'm real close to posting it but I want to get a little farther along. I think it will be interesting to see how long after I post my schematic the commerical Manzamp clones will start to appear ...........................

Great , looking forward to studying the schemo in detail.

It must be along the lines of a Bluesmaster, right?


BTW very nice chassis material - is it heavy?

[Mark]

I've noticed the chassis has four pre-amp holes and the Manzamp picture has only three pre-amp tubes.

I don't know if I buy the use of a 12DW7 in this amp though, does the tone stack need that sort of current handling?

Personally, I don't see how you can build a bad amp, it might even be better than a real Manzamp.

[ic-racer]

I've noticed the chassis has four pre-amp holes and the Manzamp picture has only three pre-amp tubes.

I don't know if I buy the use of a 12DW7 in this amp though, does the tone stack need that sort of current handling?

Personally, I don't see how you can build a bad amp, it might even be better than a real Manzamp.

One hole is blocked off on the chassis. Another mystery....

So, it is a 3-preamp tube amp and pretty sure V1 is split for the two inputs. I did try to put a ODS style overdrive circuit on the schematic, but you give up one of the inputs and volume controls. From that point I worked on it more as a hotrod 5f6a. So, I have V1 split for the inputs and V2 as a CF and V3 as the PI.

I'm expecting some big clean sound like #124 clean channel that breaks up at high volumes. I think one of the keys to tweaking this is going to be the dropping resistors and how soon it breaks up as volume increases.
In addition to the usual Precision Power Supply dropping resistors, here are also two big wire wound resistors in the power supply, just before the rectifier tube.

[PaisleyTube]

and after that we just have to wait for a D-KWS tweed Deluxe schematic and to top that on 11................

Dumble-ized Valve Juniors!

[ic-racer]

I just got back from the post office to get my resistor assortment. I ordered an assortment of 1W carbon filament resistors, which I believe is what the yellow resistors are in the picture.

The e-bay ad for the resistors indicated they will be yellow, but they came as gray. I'm not that surprised, as I have never seen yellow resistors (other than in some Dumble pictures).

It is a little frustrating that I spend months making an original looking chassis and PC board, only to fill it with no component that resembles the original, except the PS capacitors. Though, I believe, the components will all be of the same type.

[10thTx]

I'm real close to posting it but I want to get a little farther along. I think it will be interesting to see how long after I post my schematic the commerical Manzamp clones will start to appear

The commercial clones may indeed start showing up .............

One way of considering limiting this as a concern (at least for a little while) would be to not post it but offer it to the TAG members that request a copy?

Not advising that, just stating that as a thought to consider. I personally think it is remarkably generous of you to share anything of your project info. Thanks for doing so.

With respect, 10thtx

[ic-racer]

I made my final parts order to Mouser just now. Seem the 820r for the PI is not in any of the usual resistor assortments. I also forgot a fuse holder, so I ordered that.

Looking at the board in front of my, I guess I'm no longer concerned about original type components. As it stands, only the orange PS caps match the original. Every other component, like the bright blue Murata ceramic cap, is a totally different in appearance from the original.

I have the transformers mounted. I have made no solder connections yet. All the parts are just set into the board at this time.

The day I make the first solder connection is a day of celebration and from there it should move pretty quickly to completion.


[IMG768]http://img.photobucket.com/albums/v670/ ... ile-21.jpg[/img]

[IMG768]http://img.photobucket.com/albums/v670/ ... ile-20.jpg[/img]

[steve_p]

What value presence put are you using? If it is 2k, i have a few clarostats with short shafts if you want one.

Steve

[ic-racer]

What value presence put are you using? If it is 2k, i have a few clarostats with short shafts if you want one.

Steve

Thanks for the offer. Last night my long shaft 2k had an appointment with the hack saw...

I also cut the bias pot short and slotted it with the hack saw.