#102 Build started

[Ang3lus]

changed all the caps to 6PS OD, the sound is much more scooped and clearer now, with the mustards, the sound was very middy and muddy in high overdrive, now the entire OD range is useable.

ordered some Electra mepco resistors for plates, will change and report back.

[tele caster]

Thanks for keeping this updated. Very interesting. Where are you getting the mepcos from?

[Ang3lus]

got them from http://33audio.com/

email the guy, he has some values in stock.

I tested some more "mods" in the amp and i've got to say, the 68k slope with the skyliner TS (tested that with a golden ears player), loses alot of overtones, even though the sound is seemingly clearer, it gives some more gain, but in the grander scheme of things it's not that worth it.

What I did find that was a good mod is to put the NFB on a pot, at about 120k (NFB from 4ohm tap) the amp sounds best, the exact right amount of presence and bass, and some more gain, also the clean channel is as clear as the 68k slope but with the same overtones of the 150k.

again, Dumble knew what he was doing

I'm testing the amp with a few cabinets before i come to conclusions.

1. EVM 12L. (closed back)
2. 2x EVM 10M (per EV specifications cabinet)
3. eminence alnico speaker (forgot which model)

the EVM 12 and 10 sound the best, the bass don't get flabby and muddy in all settings.

evm 10 is a little brighter, the evm 12 is just perfection with this amp.

[Ang3lus]

spent some more time playing with the beast, I think i'm gonna switch to the "classic" circuit, I LOVE the robben ford tones from Talk to your daughter, and can't quite really get close enough with this type of circuit, will try switching to classic maybe later this week.

100k plates, 330pf/100n/47n TS with 100k slope is the deal right ?

[Structo]

Except Robben's #102 is a high plate skyliner.

[Ang3lus]

right now it is, but wasn't the talk to your daughter amp a classic ?

[jelle]

Yes, but why do you think it is a low plate classic?

[sepulchre]

So are you saying it was High Plate before the Skyliner mod, jelle?

[Ang3lus]

That's interesting, so it was a high plate classic tone stack ?

[Ang3lus]

so, switched to a high plate classic TS, it is GREAT for me, especially with a strat, though with humbuckers, I kinda miss the Skyliner, so I was thinking of using a 3pdt to switch between Tonestacks, thinking the POP is worth it.

I just got around to checking the fet input today, seems i'm having some signal loss at the input, gonna check it out next week and close it up when done, overall this amp is mostly done.

contemplating a Bluesmaster build next, but maybe just build a Pre version and use the other amps I have as power, I do have another amp that I will mod the PI to bluesmaster specs and maybe just build a Pre-rack version, a full build is too tiring.

Will also change the bright switch to a 3 way spdt, 100pf/220pf and off

[CHIP]

Yes, but why do you think it is a low plate classic?

According to the #124 low plate classic sticky in the Dumble Files section, "Talk to your Daughter "tones can be obtained from a Low Plate Classic (Max)

[jelle]

Ok, I agree with Max. That type of tones can be had with that version. The reality is that Dumbles have this very similar thing going on in the voicing, and this makes these Dumble Overdrive Specials sound relatively similar. So when someone who has extensive experience with these amps, like Max, makes a statement that two Dumble Overdrive Special amps from a certain era sound similar, I cannot disagree. It is absolutely true.

But why do you think that TTYD was done with a low plate? Have you built both the low, and high plate Classic, and compared them side by side?

[CHIP]

Jelle, I was just showing where Ang may have got that info. I thought the same thing, because I read it there.
I do have both a high plate and a low plate classic. I was getting pretty good "TTYD" tones from the low plate with an ES 339 a while back.
but seriously, I don't know if RF's "TTYD" was done with a low plate or high plate.

[jelle]

And I was being a smart ass. I do that sometimes, never mind that.

I think it was a high plate classic.

And I get these TTYD tones from my buddies Dumble, just straight in. Killer amp.

My own amp does this too. The low plate that I had did not do this, it got close but it worked off different harmonics in warp drive.

And it makes sense too from a historical perspective. Look at the info we have on Classic to Skyline updates. What was changed? Tonestack caps, tonestack pots, Deep switch to Mid switch. Some coax. Not the plate and cathode stuff on the preamp board. Only a partial degood would have been required for that upgrade.

But the best argument for me is the type of compression and harmonics on the overdrive on that album.

Jelle

[CHIP]

Jelle, I see your logic, partial degoop involved with the upgrade. Convincing.