My DIY Sloclone 50 Amp Build

[DrNomis]

Hey Everyone,

I'm currently in the process of working on a diy Sloclone 50 Tube amp build, it is basically a 50W Soldano SLO, but, I'm planning on using a pair of matched JJ KT77 power tubes instead of 5881 tubes as used in the original SLO 100, I've never tried KT77 tubes before, apparently from what I've read online, they are like a cross between the EL34 and the 6L6, and are supposed to be a drop-in replacement for the EL34, a mate of mine said that KT77 tubes should be a nice choice for use in a Marshall style power amp, and should sound really good, I'm also going to be using five JJECC83 tubes for the preamp and phase splitter stages.

I've elected to build the majority of the circuitry on some fiberglass tagboards I ordered online from Evatco, I love using them because they make it really easy to build the circuits, you can also easily swap out parts simply by desoldering them from the tags, although you need to create a layout for the parts first, I used some 5mm graph paper to make layout diagrams.

I've made quite a bit of progress on the amp so far, and will post some pics for you shortly with two pics of the amp chassis, as is, so.....stay tuned!!!

[DrNomis]

All I need to do now is order a set of 5 vactrols online from Evatco, solder them in place on the tagboards, and then all the circuitry will be finished, and then all that will be left to do is order the new power transformer, output transformer, choke and full set of JJ tubes, do all the final wiring, before installing the tubes, biasing the two KT77 tubes, do a full check-over to see if the amp is functioning properly, debug if not working properly, and then do a play test to see how it sounds.

[DrNomis]

This amp effectively has three channels, clean, crunch, and overdrive, channel-switching is done using five vactrols which are basically a Led (Light Emitting Diode) and an LDR (Light Dependent Resistor) encapsulated in black plastic, one of the five vactrols is used to mute one channel so it doesn't bleed into the other channel, the clean channel has a bright switch, self-explanatory, and a clean/crunch switch that allows you to switch from clean to crunch, it only works on the clean channel, I had one extra hole in the front panel located in between the mid and high tone controls, so, I added a mids switch that allows you to switch between the stock Soldano 47k slope resistor and a Marshall 33k slope resistor, this shifts the mid frequency and changes the voicing of the amp from the stock Soldano SLO voicing to a typical Marshall style voicing, there is a separate gain and master control for the clean and overdrive channels, both channels share the tonestack, the amp also includes a presence and resonance control, you can think of these two controls as being like the high and low EQ for the power amp circuit, the presence controlling the highs, and the resonance controlling the lows, on the back panel is the mains IEC socket, mains fuse, HT fuse, footswitch socket, speaker out, speaker impedance selector, 25W/50W output power switch, FX return socket, and FX send socket, yes, the amp has a tube-buffered FX loop that you can use with an external FX unit or pedal.

I built a footswitch in a small diecast aluminium box, for switching from the clean channel to the overdrive channel remotely.

I added two 3mm Led indicators in chrome bezels to the front panel, green for the clean channel, and blue for the overdrive channel.

[DaveMetalhead]

Wow, that's an amazing work! Can't wait to hear something! But there's a schematic or a layout about?