Small amp build/repair/tone question

[mitscan1]

I bought an amp on eBay that was purportedly either a professional make of the Dave Hunter Two-Stroke or some modification of that amp design or maybe similar to the Tweed Princeton. The maker is out of Colorado and no longer making or selling amplifiers. The work looks really professional to me (I would never be able to solder as cleanly as he has). When I tracked him down and called him, he wasn't super forthcoming about the amp or the design or any specifics on this particular build. It had been enclosed in an ammo box but was later transferred to a nice maple head and accompanying maple cabinet with an 8" and 10" speaker. I have tried different speaker combinations and also tube set ups -- but the amp always sound boxy and too punchy in the mids (ear fatigue very quickly). I'd like to post some photos and see if people with experience and knowledge can comment on what they see in this design and build. I hope that's a good fit for this forum. I have other questions, too, about amps -- but this is my main issue right now. Hopefully this is the right place to post this, too. I should add that the amp came with a 6L6 and 5y3 and a 12at7. I have tried other rectifiers (GZ34) and other 6L6 type tubes (NOS Sylvania 6L6G big bottle, GT6L6S, Soviet 5881WXT), other preamp tubes (NOS 5751s) to no real benefit on this issue. I had these tubes from an old Emery Sound Superbly that I foolishly sold. I have thought a 6v6 5y3 12ax7 might be the better for for this build -- but I don't have the 6v6 and 12ax7 right now. Also the builder did that the amp could handle the 6L6 tubes. You can see from the photos that there is a switch allowing use of 4, 8, and 16 ohm cabs. I have been using 2 8ohm speakers in series (at one point a Weber 10f150 and now an older 60's Gibson speaker -- coupled with a Jensen C8R. Not sure what, if any of this information is helpful -- but I am hoping you guys will have some insights. Thank you in advance.

[PRR]

Welcome!

> sound boxy and too punchy in the mids (ear fatigue very quickly)
> using 2 8ohm speakers in series

Speakers in series can do strange stuff. Especially two different speakers. Try ONE good speaker. You have the taps.

[HotBluePlates]

... I'd like to post some photos and see if people with experience and knowledge can comment on what they see in this design and build. ...

Most of my hair has fallen out, but I don't see anything in the photos that blows back what hair remains. 

As we discussed here a decade ago, the Two-Stroke is basically a tweed Princeton with 2 output tubes and a switch to select bypass caps on the 1st gain stage.

Others noted it was better to replace the two output tubes with a single-tube (which seems to have been done in your amp), and point out a mistake in the connection of the 5v winding for the rectifier tube (which also appears okay in your photos).

[octal]

Two thoughts- are you used to an amp with a standard two-or three knob bass-mid-treble tone stack? You might not like the sound of the unscooped midrange found in an amp like this.  Second thought- what's the speaker cabinet like? Open back? Closed back? Depending on the dimensions, it may have a resonance that you don't like.

[thetragichero]

my kingdom for a terminal strip to support that green wire and components from the volume control...

that being said, maybe something like the tilt/supro/big muff tone control in place of the treble cut pot? something like that tends to give you a scoop without having to add another hole for a two knob tone stack

[mitscan1]

Speakers in series can do strange stuff. Especially two different speakers. Try ONE good speaker. You have the taps.

Thanks. This did the trick. I’m glad I asked. Any opinion on a 12” for this amp? Or parallel vs series?

[mitscan1]

Two thoughts- are you used to an amp with a standard two-or three knob bass-mid-treble tone stack? You might not like the sound of the unscooped midrange found in an amp like this.  Second thought- what's the speaker cabinet like? Open back? Closed back? Depending on the dimensions, it may have a resonance that you don't like.

Thanks for the input. I have had tweed champs and deluxe and Harvard. Liked them all. Think it may be the speaker issue. Open back can. Large. Can fit a 12. May refit baffle for that. And switch to 6v6 12ax7 5y3. Maple cab is pretty but not sure if maple affects the tone.