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@neilmeansneil I don't know how many of the ROX-15 kits have been sold, but Modulus say they've not had this issue flagged by anyone else. Though, to be honest, as far as I'm concerned the only real issue is the Boost Switch. As for the DC at the master volume, this wouldn't have been a problem if I'd used JJ valves! As stated, the matched pair I'd bought some years ago turned out to be wildly 'unmatched' so couldn't be used in the application.

Thanks for the comments, I never really wanted to create any videos, but there was nothing available for the two Modulus amps I was interested in building, so did these.

I can't offer an opinion on Tube Town, though I used to buy valves from them in the past, but Modulus have provided great support very promptly to any issues I've had.

Thanks for the kind words - as for playing videos, I really am a very bad guitarist, I just like making things, but I will try and put something together when I do my final thoughts on the kit.

Hi, thanks for your comments. One of the issues I have with Modulus kits is the fact that there is nothing but the layout diagram & pick-list supplied, so there are no target voltages to measure the build against. However, as part of a discussion with Modulus about the build, they did provide a voltage chart for me to fill in, this was for each valve socket pin & each of the main filter capacitors and ask for a picture of the completed work - to which Modulus stated the wiring looked fine as did the voltage results. I can certainly show this when I do the final thoughts video later, just waiting on a few bits to finalise the cabinet conversion. One of the reasons I show some close-ups going along the board is because there are no pictures on the website for this kit, unlike some of their others.

Hi Steve, unfortunately there are no instructions supplied with the kit, you just get the layout (not a schematic, but a visual plan) to build against. Please be aware that I am by no means an expert, or even that technically competent from a trained perspective - I just like making things and as always you need to be aware that there are lethal voltages within these amplifiers.

I'm currently converting an old Marshall combo (dead amp) to take this amp, so will try and get an audio clip done. Issue I have is I'm a terrible guitarist - I just like making stuff!

Yes, I'll be putting less detail into future clips. TBH, this would be a two day ( 4 hours per day) build for me normally. Just that there was no info/internal pics about this kit, even on the Modulus site - so went a bit OTT!

As do I, though having to slow down on the build at the moment due to other things needing sorting out!

Yes, that's an option, though it does tend to leave an uncomfortable ridge and with a nylon strap you'd need to melt the edge to stop it fraying.

With the 2 x 100r resistors in place the cathode resistor measures only 42 ohms, giving a significant increase in the bias current.

Looking back over the results with the 2 x 100r resistors in place, I got the following measurements; Voltage drop across cathode resistor = 7.2 volts, so divided by the 42 ohms of the measured resistor is 0.1714mA which is halved as it's serving two valves, so 0.086mA. The average cathode to plate voltage here was 243v, so multiplied together gives 20.8watts at idle, well over the 14 watt max for a 6V6GT (150% ish).

No problem at all, the signal tube heater wires can be laid down to the back of the chassis if that proves to be quieter, I'll move those around for minimum hum when it's up and running. Many older Fenders have the heater wires positioned like this as it gives the most separation from the signal wires - I'll try both and see.