Classic or Skyliner? Rebuilding a VHT D-50

[dorrisant]

First this:

https://www.soundclick.com/music/songIn ... id=7986335

Ok... mind blown, great amp/spkr, great playing., no doubt. It is a Redplate. Henry? What did you do?

https://ampgarage.com/forum/viewtopic.php?f=4&t=9210

That was a prototype, only two were made. I don't want to clone it, just want to get close. I have built several #124s and I'm thinking that this clip is different and it might be a Classic tone stack.

Henry says the original clip from Shane should be attainable with a low plate non-HRM. But which stack?

Screenshot_20210818-002547_Chrome.jpg

Ok, Shane posted here:

https://ampgarage.com/forum/viewtopic.php?t=34157

I have Shane's (sidehatch aka Shanedawg) VHT on the bench (it has been here too long, it is starting to blend in)... it is a #183, kinda. I replaced all of the preamp board parts so it is a lot closer, but no dice. MFs and CFs in place of the oxides and ODs instead of blue Chiclets. The clean tone is there. It wasn't then it just morphed into it. (Weird, but some builds seem to do this.) It just doesn't do this OD tone at all. Its a high plate. I am hearing a lot more crunch than I would expect. What would you guys advise?

Shane said he'd never use EL34s in it, so I'm gonna put in in different grids and screens accordingly. 1k5s and 470Rs were my first choice, please feel free to convince me otherwise.

It is late and phone is dying. I will post pics and. Clear up details tomorr

[dorrisant]

No one?

[talbany]

It's hard to know for certain from just a recording? but if I had a gun to my head that sounds closer to a Skyliner than a "Classic" to me..Looks like he also has a built in loop of some kind "however" If memory serves Henry would do all kinds of mods to Dumbles circuits when he would hang out here. I don't think I ever remember him sticking exactly to the script as he was always changing something. Why don't you just ask him?

So Let's say I am right it is a Skyliner, then here is where I would go to get that sound.
low Plate Skyliner
5uF on all bypass caps
100k on all OD trimmer/volume/OD level controls
I hear NFB on V1B
250/270pF snubbers
180K OD vol feeder
All carbon films except plates/cathodes
possibly?? a 2uF Presence cap
This would be the baseline amp and tweak it from there..

The main reason for the fuzzy/crunchy sound emanating from the 183 circuit comes from several things IMO
250k on both OD Drive and OD level
No NFB on V1B
Low value snubbers
EL-34's
Type of parts Dumble used
All of these definitely added to the crunch factor with that amp
One last thing I'll add is in order to get that smooth OD you set your input vol at about 1/2 way up and keep your drive pot low and crank up the OD master along with a low 25k (or so) trimmer setting will give you that smooth OD sound..Also if he was using the loop in the recording that too would help fatten up and smooth the sound as well..
Would love to hear other opinions on this

Hope this helps!

Tony

[Shanedawg]

I remember Henry telling me that vishay dales were very important in that build. That’s all I remember about that lol!
What do you guys think?

[Colossal]

I remember Henry telling me that vishay dales were very important in that build. That’s all I remember about that lol!
What do you guys think?

Hi Shane,

I'll throw a few comments at the wall and see what sticks. Henry was very prolific and a gentleman here, back in the day. He shared a lot of ideas and designs, which can be found in the archives with some searching. That said, his designs changed a value or two here and there, and were variations on the Classic and Skyliner amps. I remember his Black Tweed Overdrive (6L6s) and I think it was the Spacedust (?) that had KT-88s, IIRC, and it was capable of very liquidy fusion tone at reasonable volumes. Both were great sounding amps, as I remember. I recall Allen Hinds being an endorser for a while and I Ithink he played a Stardust. Hinds has incredible legato (old Goldtop) and the amp (in his hands) had that singing distortion-without-distortion quality. The Black Tweed had a Skyliner tone stack and a Tweed tone (Vol and Tone) switch that bypassed the Skyliner. This gain boost pushes the overdrive toward the Violin sound when engaged. Henry would also slightly modify cathode bypass cap values, bright caps, add mid EQ shift, OD entrance tweaks, etc, so I would voice your amp where you think it needs to go (such as for more gain, if that is where your base tone lies) as you see fit for your playing, and don't be too concerned about each value having an exact Dumble reference. His amps had lots of functions for tonal variation. Henry used Mercury Magnetics for his production amps (Twin family iron). I have used many of Mercury's offerings and the Twin OTs sound very fat. Huge clarity and separation with a very fat low end. Very plump with that "poppy" Two Rock thing. Les Pauls sit beautifully there (IMO) and you get that rich sparkle and shimmering sustain with the base Skyliner sound, but never sounding woofy or bloated. So I would start there and then trim a bit of bass out of the amp as the OT will more than carry the amp's low end. You might consider revoicing the input stage (more towards Classic). Most all of the production amps I saw from RP used new stock Vishay Dales for plate loads, SBE 6PS poly film foils for coupling, a rather generic looking carbon film for signal path (probably Xicon or the like), and probably a PR02 metal film for cathode bypass, screens, etc. Pots were Alphas and EQ caps here and there over the pots were Xicon MPP polypropylene cough drops. He also packed in a two-tube reverb circuit (similar to the Matchless) and an effects loop.

Hope that helps.

[dorrisant]

Great comments guys... now I have to digest this and order some parts.

[pompeiisneaks]

I can chime in and say that from my experience, I've done the #124 and #183 builds, but followed very non standard processes. First, on 124 my first build of an ODS, I got confused and somewhat seem to have built a slight hybrid between the original and the updated verison... I'd have to double check values to be sure. I might have built the classic, or I might have built the skyliner version, I don't remember

I built the #183 with HRM and skyliner and it was done on a PCB as a rebuild of a fender blues deluxe, therefore uses fender blues deluxe iron, and the chassis. I also used all new components on both builds, so I didn't go for NOS.

I definitely can tell the difference between the two, but I'm not 100% sure which I prefer. I think I'd have to sit down with both amps at the same time and listen to them.

I really think the hardest part about this type of thing is explaining tone in words. I think the right way to do it is with your own ears...

Either find someone locally that has clones to listen to, (or better yet, the originals, but we know that's a pipe dream) and see if you can either listen to them, or better yet play them. Then you get a sense of what they sound like...

~Phil

[Colossal]

Tony, where are you right now with the input gain stage and OD Drive and OD Volume pot values? Is there a big OT in that VHT donor amp?

[Shanedawg]

After I demo’d my nephews amp Henry created this for me.
https://youtu.be/HEcr9qsDsC4

Maybe this will help with the tone I’m after.

[Colossal]

After I demo’d my nephews amp Henry created this for me.
https://youtu.be/HEcr9qsDsC4

Maybe this will help with the tone I’m after.

Hey, I remember that video!

Here is a summary of the features you mentioned:

Black n' Blues topology
6-way rotary
Two tweed and brownface modes
Footswitchable OD w/gain, volume, level (master)
Footswitchable mid boost

[Shanedawg]

That thing was a beast! I know that thing has too much going but the basic clean and overdrive is great. It seems to have the same characteristics as my nephew’s.

[ijedouglas]

Hey Tony,

Can you post a gut shot so we can see what you currently have?

What transformers do you have in the amp?

Kind regards

Ian

[dorrisant]

Tony, where are you right now with the input gain stage and OD Drive and OD Volume pot values? Is there a big OT in that VHT donor amp?

V1a - 22k input grid - 220k plate - 3k3 || 4.7uf cathode

V1b - 220k || 500pf input grid - 150k plate - 2k2 || 4.7uf cathode

OD Entrance *** - 270k - 25k trim - 15k - ground

V2a - 68k input grid - 220k plate - 3k3 ||4.7uf cathode

V2b - 180k input grid - 150k plate - 2k2 || 4.7uf

Drive pot = 100k - Level pot = 100k

There are a few caps and resistors that are on order. I subbed replacements for functional test for now.

Right now I have the stock 330pf snubber caps back in. I went to the local parts supply yesterday and came back with an assortment to try, anything from 10 to 390pf. I will try those out later.

As far as OT size... It isn't the smallest Ive seen for 50 watts but it is close. not much weight to it.

I will be out of pocket for the remainder of the day \and will try to catch up with this later in the evening.


***
"That amp needs to be gutted. Immediately replace all signal path metal oxides with metal films and carbon films. Put back a 390pf treble cap. Lower snubbers to 250pf. Then play. After assessing, you then can start replacing the preamp caps with Orange Drops. Is the NFB a on the 4 or 8 ohm tap? Make sure it is on the four ohm. Since this is a 6L6 amp, my guess is that it will sound better with a LNFB loop on V1. Consider that. Lastly, I would replace the 50k OD trim pot on the back with a 25k pot with a a 15k tail to ground. Use a 280k series resistor to feed it. This will give you far better control and make optimal settings around noon. My experience is that going to 100k OD pots will also be much better since it is 6L6 tubes as well. Make sure you have a .05uf out of V1, regardless of clean or OD. No way that thing can ever sound good as it sits. IMO.

Get rid of that .01 that feeds the OD. The .05 out of V1b is fine for the OD too. Trimming that much bass is a bandaid for other issues. Next, put back 390pf treble cap. Adds the upper mids these amps are known for. Lots of parts too swap too, like the caps and metal oxides.... start with the circuit changes. I don’t trust their ears. I played one and was totally underwhelmed."

- Dogears - Aka Audiodog

[dorrisant]

A few more...

[ijedouglas]

Hey Tony,

From what I can see there is mostly 716 Orange Drops on the board. I haven't had much experience with them (except for the Tweedle Dee build) but from what I gather in multiple other posts they can be grittier and not as smooth as the 6PS. You may want to try that to smooth it out a bit. I see there is also a MF for the OD 2 out (150/180K), maybe try a CF in that position.