Big Steel Amp - The Town & Country - Another FYD Amp.

[LooseChange]

I was asked to build an amp for a pedal steel player. He wanted something that was fairly small, all tube and between 50 and 100 watts.
We got together and he played through a bunch of my amps, his speakers, to determine what he liked/disliked about the tone. We came up with a plan...
He really liked my tweed control but wanted a traditional tone stack too.

2 x KT88 power tubes, a 6SL7 phase inverter and a 6SL7 preamp. We will be trying some 6SN7's next week to see what sounds best. Tweaks still need to be done.

Here are the usual pictures... Still using the same design formula as the Desktops... After a while, they all do look the same.  Chassis is 16x8x2 and this will be put into a cabinet for the road. The amp weighs about 22 lbs.

[kagliostro]

Nice Job - Nice amp

After a while, they all do look the same

that looks like entirely hand made standardized project

very cool

Kagliostro

[Willabe]

Still using the same design formula as the Desktops... After a while, they all do look the same.

I don't see it like that. You've come up with a design style that works very well all the way around, function, looks, sound, build quality.

It's yours. I think it's great.       


        Brad         

[tubenit]

LC, 

Fabulous job!  That looks really GREAT!   Well done. You always do such a superb job.

Did you know that Marshall made an amp called the Club and Country?

With respect, Tubenit

[eleventeen]

Where did you get the four blue (tone?) caps at the preamp end of the board? Time machine?

[TubeGeek]

As usual, very nice and neat work! Thanks for sharing.

[LooseChange]

Thanks guys.
Changed the Phase Inverter to a 6SN7. A bit less gain and sounds warmer.

No time machine, I have collected caps for years and always looking for the right place to put them. Seemed to fit this amps vibe really well.

Here is another picture of the top... I used a large Unibit (usually use a punch) for the tube socket holes. This bit made such a perfect hole, I was able to mount the sockets from the inside... Makes a nice look.

[Fresh_Start]

Admit it - the only reason you use octal preamp tubes is to make the heater wiring easier!   

Seriously, that build is too clean to be a one-off job... even though I know that's exactly what it is.  Well done!

Speaking of clean - does this circuit and tube choice give you tons of clean headroom?  Sure would like to hear a soundclip.

Cheers,

Chip

[LooseChange]

Hey Chip, Those Octals are sure easy to wire. I spend a lot of time in the design stage before I build an amp. Only minor tweaking needs to be done by the time I build.
The amp seems to be very clean. I've got the Steel player coming in tomorrow... This will be the test.

[LooseChange]

The new owner of this amp picked it up last night and gigged with it. He said I nailed it. Warm,round bottom, fat highs and clean.  You really never know until it hits the road.

[Ritchie200]

Too cool!  Congrats on a fantastic build!

Jim

[DummyLoad]

very nice work elcee.

tweed knob... nice. lol!

--DL

[Tone Junkie]

Nice build looks very sharp.
Bill

[simonallaway]

That's lovely. Almost a shame to hide it away in a cabinet :) Nice work.

[billcreller]

Very nice job on that.

[nateflanigan]

Any chance you'd be willing to share a schematic?  I've got some kt88's that need a good home and a love for big clean unique amps.
 

[Ritchie200]

Any chance you'd be willing to share a schematic?  I've got some kt88's that need a good home and a love for big clean unique amps.
 

Not to hijack, but I can not resist...

http://www.el34world.com/charts/Schematics/files/marshall/major_1967u_lead_200w.pdf

Just a personal fav!

Jim

[stingray_65]

Impressive as usual LC!

very curious as to what you estimate the power output to be.

if you get 100 W into 22 lbs I'm SERIOUSLY impressed!

I've got a Mag Comp PT rated for a 100W circuit that is 18 lbs and the OT has to be 12.

do share that formula!

[LooseChange]

I sort of winged it on this amp and don't have a schematic. I explain the circuit.

Input -> 1/2 6SL7 -> tone -> Volume -> 1/2 6SL7 -> Phase Inverter (6SN7) -> Pair of KT88's

The topology is a blackface normal channel with added mid sweep (variable slope resistor) and added my tweed control which bypasses the tone controls and provides a simple tweed tone control. It's tweaked everything to provide a clean input stage and shifted the tone control caps down to 47n and 500p. I used all the best parts I could dig up to provide the tone I was looking for. That's why I used Octals (for their warmth)

The power tube plates are at 500v, Screens at 495v. Biased around 60ma/tube. I think the OT is 6k. I had my friend at Mercury do all the calculations for the iron.  I specifically specified as small and light as possible.  The iron shipped to me was 18 lbs.

I hope all this helps.

[nateflanigan]

Thanks, that is helpful, it'd probably be more rewarding to sort out the remaining detail on my own. 

Not to hijack, but I can not resist...

http://www.el34world.com/charts/Schematics/files/marshall/major_1967u_lead_200w.pdf

Just a personal fav!

Jesus that's a lot of amp!  One could probably go with just a pair of 88's and call it a "minor"

[Ritchie200]

Jesus that's a lot of amp!  One could probably go with just a pair of 88's and call it a "minor"

 

Talk to GroundhogKen, he already has the layout.

Jim

[stingray_65]

I sort of winged it on this amp and don't have a schematic. I explain the circuit.

Input -> 1/2 6SL7 -> tone -> Volume -> 1/2 6SL7 -> Phase Inverter (6SN7) -> Pair of KT88's

The topology is a blackface normal channel with added mid sweep (variable slope resistor) and added my tweed control which bypasses the tone controls and provides a simple tweed tone control. It's tweaked everything to provide a clean input stage and shifted the tone control caps down to 47n and 500p. I used all the best parts I could dig up to provide the tone I was looking for. That's why I used Octals (for their warmth)

The power tube plates are at 500v, Screens at 495v. Biased around 60ma/tube. I think the OT is 6k. I had my friend at Mercury do all the calculations for the iron.  I specifically specified as small and light as possible.  The iron shipped to me was 18 lbs.

I hope all this helps.

Hat's off to you Dan!

I know you gig is the desktops, but there are a LOT of musicians around here that DREAM of a light weight big watt tube amp. You may have found another niche.