Marcus
Just to be clear my last post was more directed to those who want to build this amp than to you directly so Sorry if I was unclear about that!..Addressing your post here we go.
When I tried the AT7 which was a brand new EHX the amp felt a bit anemic, the tone controls didn't seem very active, as soon as I put in a 12AX7, which was a random made in china valve I had to hand, the amp completely opened up for me, the amp sounded full and the tone controls had more effect.
A couple things on this?
1st. This is a common complaint with the 2nd gen's lack of range of the tone controls!..Even people who own an original told me the same. This could be due to the higher valued Mid control and higher 1M bass (see schematic attached) as well as the James config around the bass pot and the low plates. I did, however find that it gave me enough range to dial in a perfectly useable sound!, especially for a Strat!.If I wanted a more scooped tone I had the deep and or jazz switch put me more into the blackface tonal area that was also perfectly usable....If this really bothers you then let's start small.Try removing the 002 cap on the James and split the pot with the .02 (Skyliner style) and this should help with the range of the bass pot and get rid of that weird tone shift.Let me know how this works out..2nd I never noticed going from an AT to an AX effected my tone controls given the PI is downstream from the stack (confused)I did think the AX helped to open up the amp a bit but for me was not that drastic and I lost the punch I really liked for the OD.Let us know how the new AT does.I have an old 80's Sino in mine..Good gain factor tube
When you say loud, what's your yardstick? I generally have everything running at least at 12 O'clock so I wouldn't say it's quiet.
I don't know what taper pots you have so I will just say this.I generally put these amps in the Twin/Showman class of amps, we all generally have an Idea as to how hard we need to push these amps before they start to come to life.Dumble used the same PI and gain sections in the preamp, so I generally treat them like those amps with respect to volume levels and when the amp opens up arento me real similar!
Regarding pedals, I've always thought that using 'drive pedals with a Dumble ODS was kind of against the grain as it were.
Yes I do " at times" go against the grain!.especially when I don't feel like carrying out my rack of outboard gear..Lol! This is by far my fave ODS pedal platform amp because it's a low Plate and has the AT!
The tweaks I did to mine was this!..Set it up with a fixed NFB resistor (ala Showman/Twin) so there was very little NFB (open up the output section)..Converted the presence control to a vox cut control (same one that's in the 2 rock Mayer amp).Removed the .002 from the James.I adjusted the voltage divider after V2B to better balance the vol between clean and OD..At one point I messed with the bypass resistor on the OD entrance network to tweak the gain (kitty hawk amps lowered it to 620 K I think) I don't remember where I settled on that resistor if at all but is a cool tweak if you want to get more gain at lower volumes..That's it I believe..
To be clear I am not at all against anyone tweaking an amp.My experience has been after I played the amp for a while and have gotten used to all the good things about it I don't even think about things like the range on the stack anymore I get a great sound like it is.This is also what others who own the real deal have said and have to say am glad I kept it pretty much stock..I choose to open up the output section and try to get some life there instead of the AX or in the front of the amp which can be trickier since everything effects everything else when you start tweaking the preamp.IMO it's a great amp in a different way for sure so try and let it grow on you first then tweak!..Stock cars don't come with A/C..Lol!
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m going the combo route with this so I feel that speaker choice will be very interesting, as I said I'm leaning towards trying a high powered Alnico, a Celestion cream as the original had the Altec. Any thought's on this? I have a G12 -65 available and an Eminence also that could be used, I thought if it's fender like then alnico's would be the speaker of choice.
Yeah That's a tough one!..I will say that this amp is brighter and more upper midrange focused than the high plate amps so they can be a bit on the bright side..I tried an Alnico Altec 417 and thought it was a bit much for my taste..The Celestion G-12 65 is a safe choice along with the Eminence as well as the EVL's.I prefer a closed back design for tighter bass response but that is subjective..Overall though I would say the amp is Fender-like and for the most part pretty speaker friendly just stay away from a 1k spike would be my advice as the amp has plenty in the 500/1K area.If it's a open back and single 12 a powerful magnet is always a good thing!
BTW. I have a question?..You mention
Fred, my #124 only lasted a week in it's classic then Skyliner variants before I gave up and converted it fully to a #102
Why did you build this amp!..The basic topology (low plate, Skyliner) is really similar to 124(with a cleaner PI and a less responsive stack)Since you did not like the 124 what inspired you to build this amp and what were you expecting to be different..Not to sound like an ass just curious to know maybe it will help us with the tweaking!!
Whew! that was long !!Hope this helps!
Tony
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shame I haven't got a load of NOS components.
. After years of building tweaking and playing all of these designs, the ones I've kept around have been 2nd Gen/4th Gen skyline 102/Bluesmaster/Music Man.(in no order)
) I could not combine all those sounds I listed in 1 amp.There was always 1 or 2 things I liked better in another model ODS! so I give up!..
