Is this amp similar in configuraiton to your all-in-a-box 102? if so, does it have built in loop with cable compensation caps (180-200pf) and 68p on the master vol??
On my own 102, which has a classic stack, but high plates, the 68p didn't do much good with the classic stack. And also, IMO, the 102 need much more volume in order to 'open up'.
My Low plate 50w classic and #183 (with classic stack) - and off course tweedle deluxe with classic stack - are much more responsive at lower volume levels.
No built in loop, but I am using it with an outboard Dumbleator and somewhat short cables in the video above. I've got the 68pF master bright cap on a pull-switch. Without the Dumbleator patched in, the amp in it's current form sounds better without the bright cap. With the Dumbleator it really seems to need the cap. Either way it seems to be missing something sonically to my ears/hands.
It does seem to sound better as I turn it up, though. I haven't played it with a band yet either, so it may come to life more in context.
ToneMerc wrote:I've found that none of the circuits are " one stop shop" and there are compromises with each. I love the LPC for strat cleans, but not so much for the OD, unless it's the funky entrance , 12AT7 PI and the early GNFB, but that's a different rawer OD. Also, I like the LPSL with the Dumble PI for OD.
FWIW Aaron you would sound great through a Pignose and $69 Strat.
TM
Thanks TM! I can definitely see how the different variations have their strengths and weaknesses. This is really an explorative, learning task for me. I wan't to get a feel for what the different topologies do and am using this amp as a testbed to try things out. Listening back to the video, I think maybe it FEELS worse to play to me than it actually sounds.
bluesfendermanblues wrote:what about the OT and the Feedback circuit....could it be too stiff for the OT or is the amp (caps) not played in yet.
Could be, but it sounded awesome as a high plate skyliner so that rules out the feedback circuit I think. Only really 3 new caps. Treble, mid and the ceramic in the deep filter. I suppose the 2 tone caps could need to break in more.
aflynt wrote:Here's a clip of the amp in Lowplate Classic configuration with a Les Paul. Trimmer set to around 38k to ground w/od on. Starts out with OD level set around noon. Lower gain later and switch to clean. I engage the deep near the end.
bluesfendermanblues wrote:Try disconnecting the LNFB...it's not part of the low plate classic setup and probably the reason why you perceive a certain hardness to the sound.
and also as you menitoned above - the classic has a 100KA mid pot and not the 250KA - so you will probably wnat to dial the 8250K) mid pot in lower.
If you still have the 1n on the bass pot, try lifiting it. It also ads a tiny bit tone sucking, IMO.
Thanks for the compliments and help!
The amp is pretty much exactly like this layout right now:
aflynt wrote:.............. I thought many low plate classics had LNFB?
-Aaron
No-one really knows for sure..............but Heisthl has the LNFB on a switch on the back of his amps as well as a switch with an extra cathode cap for v1a (probably with 20uf upping it to a total of 25uf on V1a).
Henry calls the LNFB and cathode cap switches e.g. on the BluesMachine66: "Rear Panel Voicing Switches - Humbucker and Smooth Compression switches".
Hello Aaron, first of all, I like the sounds your getting with both of your clips. It doesn't hurt that you play well either. I looked at your layout and other than the 250pf snubbers(mine are 270pf), we have the same circuit. As this is my first ODS build I don't have anything to compare it with. I would like to suggest trying a preamp tube v1 with plate voltages at around 190v. I find the OD sings a little nicer and the clean feels a bit looser. Do you prefer the Strat both clean and dirty with the 102 Skyliner?
CW
Aaron I just noticed from your layout that you have 47uf filters on your clean and OD and 5uf bypass on clean rather than 10uf. The 47uf probably stiffens the front end a bit and the 10uf bypass rounds out a Strat a bit. Just a thought. Also, do you still have that network on your send and return?
CW
I got out the alligator clips and started to experiment today:
I actually like the LNFB in place. Bumping up the V1a and b bypass caps to 9.4uF helped immensely. I only had a bunch of 2.2uFs on hand so I paralleled 2 w/the existing 5uF on each cathode. I also wound up installing a 250k OD trimmer (now set to 35k), and tried out a treble bleed circuit (1M pot in series with .0012uF cap to ground off 150k / Ratio pot input).
The higher bypass caps seem to have brought the life back to the amp. The 250k trigger and bleed circuit (set to around 82k) got the 2 channels sounding more balanced tone and volume wise and also sweetened up the OD in a way I prefer. It was just a little too hyper-articulate and anemic before.
Charlie: The loop network is still there but I've just been bypassing it with a short cable when not using the Dumbleator. V1 and 2 are both in the mid to high 190's on the plates with the current glass. The amp feels bouncy-but-solid with the lowish preamp plate voltages and higher (465-470vdc) power amp plates.
Now I just need to solder the values in there and hope it still sounds good!
Sounds like you are getting there. I may try your 250k OD trimmer and a HF taper also. I notice some of the classic ODS had higher value OD trimmers. #94 had a 1 meg and a .02 HF taper with a trimmer set to about 100k. Please more clips when you make the changes. I want to hear your amp and steal some licks.
CW
I've got the tweaked values wired in now. I'll replace the little googly eyed parallel cap creatures once I get some 10uFs in. If I decide to keep the HF taper I'm thinking that I'll RTV it to the top of the V2b coupling cap to keep it immobile too.
Incidentally, after listening back and forth a bunch of times, the HF Taper trimmer sounds most balanced against the clean channel when set to about 188k, which sonically is about where it just starts to have a perceptible effect.
-Aaron
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