Express with 6L6's?

[guitardude57]

Howdy Guys, Mark and RJ,

got porn.......

This is a weird one RJ......... when you see the guts you will have a better grasp of what is what. This has been a couple of different Marshall circuits, I then decided to try the TW Express type circuit config. This one might stay in here a while....big fun!

The steel chassis has been a good experimenters' format....large real estate to play with.

The voltages are not consistent with Normal dyed in wool set up. Nor the layout. At all. B+ rails are set up for easy value changes to alter any voltage to any tube with easy. A true experiment in terror.........

I have 467 V on the plates, 411 on the screens.
Going to drop the plates a few volts when I can re-up my parts....getting low. But at the moment (30 hours or so of play time) no problems.

The gut shots are just prior to putting in the sockets and guts for the 6L6's.
The outside shots have the big bottles installed.

Shared plates, grids and screens supplies, and different Plate, Screen and Cathode Resistors for 6L6's versus 7189's. Want a little more jangle, pull the 6L6's and pop in the 7189's and go.

The 6L6's are Soldano Branded Sovtek 5881's and used for about a year before I put in a matched quad of GT's in the SLO. Nice bright, warm mids and nice bottom. Sort of like my Wife!

So, an interesting variety of tones between the 2 tube types. I'm having fun, and besides it cost me 14 bucks for the step bit to cut the holes out for the octals. Everything else was parts on hand......basically free/recycled parts. Some I've had for 20 years looking for something to do.

I need some 1M pots.....using 500K on Volume and Bass, 250K on Treble and 25K on Mids. !0K with a turn-off switch for Presence/NFB.

This damn thing is a grinder with NFB off! Somewhat noisy because of total disregard for layout, but under control. Just mainly louder hum.

The Bright switch actually turns on a bypass cap on V2 in off position. So it is plenty bright for me with no bright caps. Nice subtle difference.

The boost switch kicks in a bypass on V2 plate for extra umph. Like I really need it. Was an experiment for grins. Haven't needed it......just kinda there still.

My axes are being borrowed, so my Strat with Hot Rails in the bridge and middle, and a Duncan Stack Strat in the neck sounds quite nice.

At 2/3 volume on amp and 4-5 on guitar volume, is clean like Robt Plants "Big Log". Crank a little more and CRUNCHY! Dime the guitar and I can get sing and grind to hearts content. Controlled feedback on just about any note on the neck.

Soon when Wifey is running errands I will record some tracks for ya.

[guitardude57]

A couple more shots.....

[RJ Guitars]

Very Cool - thank you! Have you played other wreck clones? I was curious how her sound and behavior compares? thanks, rj

[guitardude57]

RJ,

No, I haven't had a chance to play through any type of Wreck amp.
I have listened to Glen's on You Tube. and a few others. I would say pretty close to what mine sounds like.

I won't be able to truly compare until I get the right value pots on mine. The bass and volume are 500K.....and very old, so that throws the tone stack off. I didn't have double value Caps to line it up. The PT has 2 heater taps, the 3A is going to the big tubes, so will be interested in getting some EL 34's in there to make a better comparison to Glens'.

The 6L6/5881 tubes sound good to me. The tubes are in decent shape so no regrets to them being used. Between mild circuit differences (values of a couple resistors I didn't have) like using a 2K2 instead of 2K7, and using .047 couplers to the PI ........since I didn't have any more .1's. Might even make some .1 caps switchable when I get some. Plenty of good tone with the .047's. I am pleased.

I have a single JBL cab, a single Celestion 75 watt cab, single EV 16R cab, and the 4 X 12 with EV's to run through. All are distinctly different sounding.
I will likely do clips comparing them.

In any case, I really like to play this amp. Pretty motivating.

[Richie]

I like the sound of the .1ufs in the PI. on the express.

[M Fowler]

I like the PTP layout I am a sucker for that. Great use of old parts to getting a grinding amp out it all. Having fun aren't you.

I will be starting on a PTP Gibson EH150 soon your amp is getting me geared up for that.

Mark

[guitardude57]

Yeah Mark,
Nothing like a (almost ) free amp that kicks butt.

A Buddy of mine has a Gibson 100 watt Titan, I've been trying to talk out of him. It was his Brothers' bought new in 1966. Hell, half the band would plug into it. A 15", a couple of 10"s. Big volume.

So far no luck getting it. It has been in the attic for 25 years. It worked......but was quirky and unreliable. I might have to swap my Plexi Jr for it. Maybe some day.

So he has drug around a couple of Gibson L 5's, use 1 until it would go south.....pull out his other L 5.........use that one for the gig, and fix the other as a back up to his other. At least 50 times over the last 25 years...LOL!

I am amazed either still works. Most probs have been cracked solder points, pots and the occasional resistor. I think all the caps are original.

His sound is total peddle oriented, so a generic SS amp works. He is an awesome player, but his tone always sucked ass. Sounded like 6 Boss peddles into a SS amp.

For his Birthday 4 years ago, I bought him a brand new Mesa Nomad head, that sounded great. At last.....tubes for Dale.

He loves it so much it doesn't leave the house............. oops.
A 900 dollar, at home amp. Oh well, he's worth it. Great friend.

So you have the iron and whatnot for your Gibson build? Chassis?

My next one, I'm thinking will have a piece of diamond plate aluminum and a couple of 2" angle pieces for a cheap and stout chassis alternative. Shiny side up! Layout on a flat piece of metal would be cool. Then bolt on the angles.
Circuitwise..............maybe a AB763 reverb channel.

Since I use one of those rack switchers, I could use a big headroom clean amp for a change of tone. We'll see. Between the SLO and the Langner, I have about all the bases covered.

But we have to tinker, right?

[breakfastbuddy]

this comet conkorde , the tone stack is on the end of preamp or at the beginning ?

[guitardude57]

Hey Beakfastbuddy,

Welcome. We are discussing an Express type circuit here.

But according to a schemo I found for a Komet Preamp (do not know of accuracy of this) the tone stack is after the first stage.

See diagram below.

I haven't taken much time to review the copy of Doc's passed around a couple of weeks ago. It is on my to-do list.

[guitardude57]

I finally got around to replacing my volume pot with a 1meg. The amp has more gusto now for sure.

But interesting....at about 90% volume and up to max, getting what sounds like blocking distortion. As it is turned to max, sounds blatty. Under 90% volume sounds good.
At least that's what I believe is happening. Any ideas? Haven't encountered this phenomenon in other builds before. What ya think Mark?

[Bear]

I saw the EV logo on the domes through the grill cloth and a tingle of fear went through me. I've got an EVM-12L in a TL-806 cab, and that thing gets scary loud with just 8 watts going in. I can't imagine needing the 412 unless I were covering MBV's You Made Me Realise and needed mucho SPL. (I'd link to a video, but nothing really captures the room pulsing and shaking as it is completely saturated with sound.) All the same, that's gotta be fun as hell to play through.

[guitardude57]

Yepper, it is a great sounding box. I also have a 2X12 Marshall slant, also loaded with EV's. It is what I have used for speakers (EV 12L's) since the mid 70's.

[Roe]

personally I like a 250k volume pot - it gives less hiss than a 1m but still sounds good

[JamesHealey]

See the input sensitivity of the control grid on EL34's and how easily they clip is part of that 'Wreck Magic' same goes for EL84s.. You start to use tubes like 5881, KT66, KT88 you're going to be changing how the PI and the Power section react.

The magic of the wreck comes from the fact the power tubes are clipping first then the PI, then the asymetrical cold clipper and back to the first stage eventually.

I've noticed even when using 6V6's which are commonly accepted as a wreck subsitute, they are much smoother/cleaner sounding, I quite like my Wreck with 6V6's but the only reason im using these is to reduce the volume a tad, also using a 1x12 cab.

[Cliff Schecht]

What 6V6's are you using? I've found that Sylvania's from the 40's to early 50's sound fantastic in an Express. RCA's weren't as ballsy and none of my other 6V6 pairs sound as good as the ones I have in there now (military surplus from May 1945). I would say fairly close to the EL34 sound, a bit smoother in the high end and yes just a tad less volume but they don't clean up as well either, at least for me.