80s Mod Board in the works
- Thread starter V2a
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V2a
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fusedbrain":1vo9thkb said:
To my knowledge, the Dirty Shirley is not like the other Friedman amps that have the topology that you described. I don't want to give away anyone's trade secrets, but I do want to clarify Mod Board installation and stability issues. So I will say this: You can max out the gain of V1b in an otherwise typical 2204 preamp without oscillation. You can even increase gain on the input channel. You need not re-work the preamp into a Jose circuit as described above. But you do need a good layout. It all depends on lead dress, the grounding scheme, and component spacing. When the going gets tough, you can add anode bypass caps to remove high frequencies that you probably won't hear anyway.
Kapo_Polenton
Well-known member
V2a":2caipral said:
I dig my mod board too! Just a note to people installing it though, make sure you measure twice before drilling. I think my drill slipped and I ended up with holes that were too tight so I had to widen them and it looks a tad like a hack job. That said, I used a washer to hide my errors and you can't tell.
I am going to do a few clips when I am off next week. I dig it. Just gives you a bit more of everything compared to the stock circuit. I have a good sounding 2204 though so you need to start with something you like.
V2a
Active member
Thanks Kev.
There is very little room for error when dealing with miniature switches because of their diminutive size - the stock nut won't cover up any booboos.
I recommend getting an automatic centre punch and actually practice the punch many times using the drill template. Once you get the hang of lining up the centre punch, then its pretty easy to drill first with 1/16" and then gradually moving up to 1/4".
There is very little room for error when dealing with miniature switches because of their diminutive size - the stock nut won't cover up any booboos.
I recommend getting an automatic centre punch and actually practice the punch many times using the drill template. Once you get the hang of lining up the centre punch, then its pretty easy to drill first with 1/16" and then gradually moving up to 1/4".
V2a
Active member
More Mod Boards in the works. I'll build more of the original 80s Mod Board and a new Deluxe Cali Clipper (DCC or CC+ ??). Can't wait for the parts to arrive!!
I'm gonna load the CC+ into each of my Caldera amps, which already sport a front-panel structure switch (labeled 'punch').
I'm gonna load the CC+ into each of my Caldera amps, which already sport a front-panel structure switch (labeled 'punch').
I just saw a Soldano Atomic 16 for sale local to me, do you have install instructions available for it ? I’ve been gassing for a good, all tube high gain combo to bring out... I’d want a depth pot added and maybe a Metro loop too, can all this stuff coexist in the amp ?
V2a
Active member
paulyc":2ggnivgi said:
I have a reasonably long installation document that focuses mainly on 2204 amps (including turret-board and PCB builds). That document refers to the Atomic 16 but doesn't go into specific details for that amp. I could provide additional notes on it, based on the schematic and gut shots I have seen. I haven't been inside that particular amp, however, so my notes would be for guidance only.
Some initial notes:
- the Atomic 16 preamp has three gain stages like the 2204, with an unbiassed 2k2 cathode resistor in the second gain stage (2204 has 10k resistor in that spot). My stock structure switch works with a unbypassed 10k resistor, but we could modify the Mod Board or the Atomic 16 PCB. Or you could opt for the Deluxe Cali Clipper which doesn't have a Structure switch.
- the Atomic 16 has a cathode-driven tone stack like the 2204. The Cali Clipper switch could be inserted before the tone stack as done on the 2204.
- It looks like it would be reasonably easy to access the bottom side of the PCB simply by removing all pots. I could be wrong, but if that were the case, then it should be pretty easy to connect the mod board to the right parts on the PCB (four wires need to be connected).
- it might also be possible to solder to the top side of the PCB in that amp. Again, this would simplify installation of the mod board.
- the Mod Board can coexist with the other stuff (loops, depth mod). You just need to find the room on the back panel for everything.
I'm currently all out of Mod Boards, but I have a shipment of boards coming in and will order parts this week. I'll add a Deluxe Fat switch to the family of back-panel Mod Boards.
Cheers, John
Junk Yard Dog
Well-known member
V2a":3p3jqjej said:
This is a GREAT thread (though a bit too technical for me). BUT, I have a 2016 Egnater Boutikit that I am interested in modding further. I know you know these Eggies pretty well, and I have some questions for you which I can send in a PM.
I also want to clarify: can you add Punch/S switch and Cali Clipper to the
Also, is the CAli Clipper similar to the Era/Sat switch on the Ceriatone Chupa/Yeti, in that it makes the amp higher gain, and it lowers the volume?
What are the impacts on the tone? And can we get a pic of what they look like on the outside of the amp?
I may be interested in adding this to my Boutikit if it can get it to cop some very angry CCV like tones. It’s alreadg a badass amp!
Cheers!
V2a
Active member
Junk Yard Dog":3gon7eut said:
The original (80s) Mod Board has the Structure switch and the Cali Clipper. I added this board to a 20W Egnater Boutikit, so I know that it works well in that amp. I think you wanted to confirm that these functions can be added to the Boutikit, but the text was cut off in your post.
The Cali Clipper is similar to the clippers that are in the Ceriatone Chupa/Yeti in that both add distortion and drop the volume.
Tone comments are always subjective. In an earlier post, Kev said that it sounded like his stock 2204 but with added distortion (or whatever; I'm going from memory). My clipper implementation tries to strike a balance between added distortion and "tube tone". The Chupa adds more distortion than mine. But the Mod Board itself is modifiable....
Will the Mod Board make the Eggy sound like a CCV? I doubt it. I haven't seen a CCV schematic, but the schematic of the Fortin Cali that I have seen has a lot more filtering of the upper end. I think the Chupa does too (both the Fortin and the Chupa might be based on a Cameron amp). But it is easy to tweak the Egnater Boutikit circuit to get a little closer to the chugga-chugga of those amps.
Feel free to shoot me a PM if you have more questions.
Here is a photo of an Egnater Boutikit amp with Mod-Board switches.
V2a
Active member
scottosan":19ohkbhd said:
Yeah, I suspected that might be the case.
peterc52":19ohkbhd said:awesome. I would guess they would fit in a turret board marshall anno 1970?
You'd have to cascade the inputs and then change the cathode resistor for the second gain stage to make the most of the Mod Board. And ideally add a master. Info on these mods are all over the web; the cascaded-inputs mod might be called a 'one wire mod' (someone else might be able to confirm; I've never really looked online). You can have a look/listen to MichaelR/T's sound clips right here on Rig Talk. It would be quite a new amp at that point.
Kapo_Polenton
Well-known member
V2a":30d7m0hh said:Something new just installed in something new...
I have an extra tube in my Laney I could use for something like this but given how hard it was to keep the noise under control with the existing mod board I put into place given my own layout (not the product), I think I would be fighting some major noise issues!
V2a
Active member
]The board in the photo above is a three-position FAT switch. Middle is tight, up and down add a little or a lot of low end. Could be used in 2204 type amps, especially in conjunction with the 80s Mod Board that kicks up the gain. I've currently got it in a higher-gain amp (four gain stages instead of three).
Do you need the little board? No. But without it, the switch looks something like the one below (this one is a two-position version). I prefer the PCB approach; it's cleaner, and the parts are more secure.
Do you need the little board? No. But without it, the switch looks something like the one below (this one is a two-position version). I prefer the PCB approach; it's cleaner, and the parts are more secure.
V2a
Active member
Here's Kapo_Polenton jammin' on his hand-wired 2204 clone after installing an 80s Mod Board. Cali Clipper was on throughout clip. Structure switch in middle position (lowest gain) at start. TS808 on at the 42 second mark. At 2:06, TS808 turned off and Structure switch set to highest gain setting.
Thanks Kev!
Thanks Kev!
Kapo_Polenton
Well-known member
It really is a great little board. Love the Cali clipper, just gives the amp that little bit more. Structure switch is great too in the highest gain setting. I bet this thing will track great and hope to try that sometime soon.
V2a
Active member
I finally got a chance to install some of my Mod Boards in a JCM 800 (a 4104, to be exact). The amp was very anemic when it arrived and needed quite a bit of regular maintenance. The owner had already purchased some replacement filter caps (JJ brand), so I put those in at the same time.
The end result is FANTASTIC! But the journey was also pretty fun - and a great learning experience (only my second time inside a vintage Marshall).
I'm going to update my Mod Board installation manual. If anyone needs help with their Mod Boards, let me know.
The end result is FANTASTIC! But the journey was also pretty fun - and a great learning experience (only my second time inside a vintage Marshall).
I'm going to update my Mod Board installation manual. If anyone needs help with their Mod Boards, let me know.
Kapo_Polenton
Well-known member
It's a great board people, no brainer. The base 800 tone is there if you want it. No thousands spent or hacks to your PCB.