Hi,
This is my second thread here on this great forum board.
I always wanted to build my own modules for the Egnater M4 and started with a prototype of the module about a year ago, which had a few bugs with regard to mechanics and getting a few parts which are more suitable for a one off production.
After the prototype was built, which in the meantime has been binned, I started with a Trainwreck module. https://tubeamparchive.com/viewtopic.php?t=18038
Now I finally finished the Dumble #102 preamp in module size.
It sounds great like expected and IMO less noisy than the original Egnater modules.
In addition to the original layout of the #102 I added a 500k trim pot and a .022uf capacitor to voice the overdrive channel.
The Bright and Deep switch have two settings. The Jazz/Rock switch has PAB in centre position.
For the front plate I used dry clear decal which is cheap and does the job I think.
Feedback welcome
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I don't know the exact architecture of the Egnator platform, but I'm sure you have a reason for choosing the input resistor values at V1a.
The 68p on the Master vol is compensation for long leads (180-200pf) from the preamp to Dumbleator. Is it needed in the Egnator amp or do you simply 'unbright' the amp with the trim+ cap at the OD level pot?
I don't know the exact architecture of the Egnator platform, but I'm sure you have a reason for choosing the input resistor values at V1a.
The 68p on the Master vol is compensation for long leads (180-200pf) from the preamp to Dumbleator. Is it needed in the Egnator amp or do you simply 'unbright' the amp with the trim+ cap at the OD level pot?
Will you share the layout of the PCB?
Thanks !!!
The Egnater has a tube stage in front of the modules. I adjusted with the resistors the input level into V1a to achieve guitar level. You are probably right, the 68p on the master can be taken out which probably will reduce some brightness of the clean channel. Will give it a try. Yes, the trim + cap makes the OD less bright to my taste. Which I shall review while playing with the 68p on the master. Thanks for the hint.
PCB layout attached ( green trace is back of board, gray traces are top of board) I design in AutoCad, which is obviously not a standard for PCB layouts
The input resistor with 470k has changed to the 3 resistors as shown in the schematics. OD voicing not shown on the pcb as I post installed it.
You do not have the required permissions to view the files attached to this post.
I don't know the exact architecture of the Egnator platform, but I'm sure you have a reason for choosing the input resistor values at V1a.
The 68p on the Master vol is compensation for long leads (180-200pf) from the preamp to Dumbleator. Is it needed in the Egnator amp or do you simply 'unbright' the amp with the trim+ cap at the OD level pot?
Will you share the layout of the PCB?
Thanks !!!
The Egnater has a tube stage in front of the modules. I adjusted with the resistors the input level into V1a to achieve guitar level. You are probably right, the 68p on the master can be taken out which probably will reduce some brightness of the clean channel. Will give it a try. Yes, the trim + cap makes the OD less bright to my taste. Which I shall review while playing with the 68p on the master. Thanks for the hint.
PCB layout attached ( green trace is back of board, gray traces are top of board) I design in AutoCad, which is obviously not a standard for PCB layouts
The input resistor with 470k has changed to the 3 resistors as shown in the schematics. OD voicing not shown on the pcb as I post installed it.
If you try it without the 68p at the master, you might like 220p across the OD level (instead of the 22nf with trimmer).
On the other hand if you keep the trimmer pot, you might like 1nf instead of the 22nf.
If you try it without the 68p at the master, you might like 220p across the OD level (instead of the 22nf with trimmer).
On the other hand if you keep the trimmer pot, you might like 1nf instead of the 22nf.
Your PCB could be a nice pedal with proper PSU
Cool. You are right, the size and layout is the perfect platform for a pedal.
Never touched PCB for Tube amps before, but it perfectly works. Only repairs can be quite a pain.
I currently have a Mesa Boogie 22+ on my desk with an upside down PCB board and an intermittent power supply hum. A pain to find the source.
I don't think those amps ever caught on but they seem to have a lot of versatility.
Thanks Structo
Very versatile, you are right and you will be surprised there is a huge community of musicians who are using the Egnater M4 and Randall RM4 module amps. If you are into 19" stuff, then this is a great thing to have and not many would like to miss their module amps. The advantage is that you always can carry at least four amps in your rack with you.
And if one can build his own, there is no limit... ( not including that power amp section and speaker cab have a huge impact on the sound as well)
At least lots of fun for experiments and it doesn´t take much space to keep.
__________________________
We love to have fun and that is what amp building is about.
LeftyStrat wrote:I'd be interested in knowing how the M4 distributes power to the modules, ie. what voltages. It looks like you have onboard regulation, correct?
Very nice work!
Hi,
The M4 provides +320V and +18V. The 18V are regulated to 12V on each module for DC tube heating the relays for signal switching.
__________________________
We love to have fun and that is what amp building is about.
Your PCB could be a nice pedal with proper PSU
