5E3 Volume Tone mod

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One thing thats not so great about the BF stack + 5E3 is the insertion loss of the TS.. You don't get much output at all and it sounds kind of flat like that (imo, have been here). If you got space, I'd suggest you pop in a socket for an extra dual triode just in case.

I did a sort of Harvard tube complement, 12AV6, 12AX7, 12AQ5 and stuck a TS in there, while there is not a lot of gain, there is enough to get the output to overdrive mildly. If I need more I can change to the Tweed side of things. I like the BF tone stack more for cleans anyway.


On a more disturbing note, wiring things up I noticed the TS is still hooked up to the output of the 5E3 normal channel. OK how did I miss that before? Theoretically it will load down at least the midrange depending how the TS controls are set. I'll have to give this more though, may just try it and see how much it impacts on the 5E3 side of things.

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Seemed the eyelets were anodized aluminum rather than brass or brass plated steel. Real hard to solder. I had the parts already in the board and said the heck with it, it is just a prototype and I just wanted to see if the circuit would work. I twisted the leads of the parts in the back of the board into a ball and soldered them together. Well so it sat for months as I could not bring myself to finish it. Eventually I removed the parts and made a new board with some home made turrets.

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Got is partly together, I was unsure if I was going to run 6K6's in it or 6V6's, also wanted to sort out the amp section without worrying about the controls and switching. Have 6K6's in at the moment. Put it through a 8" speaker, the little amp has a bit of a bark to it.

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Had the grid resistor on the wrong side of the grid stopper on the PI stage. Don't think it mattered much but changed to the right turret. Had some crazy voltages on the 12AX7 tubes. Started swapping them around, some others in and out, finally found a couple that both triodes worked properly. Put a 12AY7 in the first hole, almost made to be there.

Have some noisy pots and maybe a bad switch. That is what you get for buying cheap stuff out of China. Otherwise even on the bench with the bits and pieces spread all over, long leads, no centertap on the heaters, the thing is pretty quiet. The power transformer is cool to the touch so it probably could handle a pair of 6V6's. May have to put a switch in to change the cathode resistor to accept them. The 6K6's sound pretty nice though.

I am going to have to wire up the tone stack and sort out the crappy switch and pot. Then I can decide if it is worth doing the different modes or which to keep. I am pleasantly surprised on the Hammond 125E output transformer. It has multiple taps so you can chose between a number of impedance ratios. I never noticed it only had a low inductance of 3H. You would think it would have poor bass response, actually is not that bad. I was going to get a different a different one but may just keep this one.

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Had the amp sitting on my bench for a while. I have been going back and forth between the 5E3 volume-tone configuration and the normal voltage divider arrangement. A little different but generally the amp sounds the same. The BF tone stack is nice to have also but it really sucks gain. Just not enough to get the amp to break up. I could rip apart the amp and rearrange it to do either the 5E3 or the Brown volume-tone and then switch to the BF with the triodes cascaded. Not sure what I will go with yet.

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Think I may try this. Use the two triodes in series with the BF tone stack in between them. For the tweed going with the regular resistive divider volume and tone stack with both triodes paralleled up. I may switch out the low frequency cap of the Tweed tone control when in BF mode but leave the high frequency cap to act as an adjustable bright cap on the volume control. Still have an extra set of contacts so if it is a bother I can switch out the bright cap.

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I did a couple changes from the last schematic. No jack for the boost on the last preamp gain stage and I used a four pole toggle switch and I decided to switch out the tone pot wiper when in blackface mode. Went to full sized pots and decided on a WGS Veteran 10" for now. Still need to make some back panels for it, mount the chassis, find a handle for it and do the grill cloth. Otherwise it is playable and sounds good in Tweed attire or dressed up with treble and bass along with a good helping of gain. Oh yeah, going to have to label the controls, not sure how yet but the SS looks good.

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Used the 5E3 to 6G3 (sort of) switch in a little 5E3 I just finished. All of 2W, well maybe 3W. 6AK6 output with 230V on the plates.







360 ohm on the output cathodes. Dropped the 4.7k resistor past the doubler.

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So I did mp3 of a work buddy trying out the 6AK6 amp. He has never played a 5E3 so he didn't know how to get the most of the controls. Please be kind to him as this is his first time playing it. I put it on a Microsoft sharing file place, first time I used it also. If you want to hear the amp you can download it.

http://1drv.ms/1hDNpt3