I have no idea what you refer to on the ODS101 schematic. Especially since I was very instrumental behind the scenes in proofing it. There is a 50k/50k divider before the 1M master to load the OD2 correctly. It simulates the 100K level pot. This is in there, at my suggestion, should someone want seperate masters. So in this case, there would be two 1M masters in that amp.
I guess it also means 123 had seperate masters?? Maybe a first for a non HRM amp! Certainly possible....
As far as the 500K trimmer, one would need to actually measure it and most people I knwo that have gone into these amps just notate the parts value stamped on it. Based on Billy and Gil's finding regarding 124, I'd tend to think the 500K is not all it seems. Unless we have pictures.....
ElectronAvalanche wrote:
So you are saying that the OD fed directly into the 1M master with no level? #123 would have a level control on the chassis. You sure your notes are correct? 150K into 100K pot w/HF trim control. Then into master?
Hi Scott,
I guess I was not quite clear enough with the "from the ccw of the 1M to 500k pot to 0.022 uF to ground" part in my posting. "ccw" would mean on the input side of the OD Master.
Look at the ODS101 schemo: 0.005 uF OD2 decoupling, into 150k, tone pot (500k, cap to ground) into 1M OD Master from there to PI.
The 500k reading of the input pot of the OD was measured by someone who I think knew what he did. I did not measure it myself.
I have no idea what you refer to on the ODS101 schematic. Especially since I was very instrumental behind the scenes in proofing it. There is a 50k/50k divider before the 1M master to load the OD2 correctly. It simulates the 100K level pot. This is in there, at my suggestion, should someone want seperate masters. So in this case, there would be two 1M masters in that amp.
Hi Scott,
look at the attached schemo of the ODS101. Between the Ratio and 150k there was a tone cut in the #123. The Ratio was 1M in the mentioned amp. I call Ratio the OD Master Volume.
Cheers,
DominiK
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Yea, this is a common spot for the treble bleed (as we call it). But the question is whether 123 had seperate masters, or did it have a 1M cascading into a 1M. Or, was it a 100K with a 1M cover! If it were measured, you should have notes saying 983K or 1.02M, etc.... If it wasn't measured, then it very well could be a 100K in disguise...
Btw, check your PM!
ElectronAvalanche wrote:
I have no idea what you refer to on the ODS101 schematic. Especially since I was very instrumental behind the scenes in proofing it. There is a 50k/50k divider before the 1M master to load the OD2 correctly. It simulates the 100K level pot. This is in there, at my suggestion, should someone want seperate masters. So in this case, there would be two 1M masters in that amp.
Hi Scott,
look at the attached schemo of the ODS101. Between the Ratio and 150k there was a tone cut in the #123. The Ratio was 1M in the mentioned amp. I call Ratio the OD Master Volume.
ElectronAvalanche wrote:Between the Ratio and 150k there was a tone cut in the #123. The Ratio was 1M in the mentioned amp. I call Ratio the OD Master Volume.
Cheers,
DominiK
Every now and then I get visions, and now is one of those moments. I can clearly see #123 on a big island type of place... Australia!
Gil
Last edited by ayan on Tue Nov 13, 2007 11:47 pm, edited 1 time in total.
I do recall a post that stated that Dumble would ask a client what kind of guitar and especially what pickups would be used with the amp. He would use this info to decide what specific ckt he would use. Cool to see two adjacent serial numbers with really different ckt's....
I built an exact clone, pretty much part for part from 124 when Gill originally posted it. I did it on a Blackfaced 60's Bassman chassis. It was 100 watts /w Fender twin Iron. I used all sprague atoms caps and Ps series, tone caps as well as 100k/1.5 through out as well as 10uf bypass ,Voltages came in real close within 10 volts of 124, throughout. It was also a brown sounding amp as well
My Verdect
The amp loved humbuckers!!! in overdrive it was thick rich and had a really nice knarl. This was the type tone where you dont have to muscle any notes, I got an excellent snarly thick rich type tone and still keep a fairly light touch going on. (one of the few amps Ive played that had this vibe) roll back the vol and the amp cleaned up well, but still had the chirp when you leaned on it. The neck pickup was a bit on the darker side but still felt pretty good
I can see why someone would spend most of there time there.
One thing of note was the more you pushed the amp the better it sounded. The midrange was in your face just enough yet not painful. skyliner .01
As far as the clean channel goes, I preferred the single coils here over the humbuckers, I like my clean tone to be mostly clean just on the verge of breakup, the humbuckers didn't clean up as nice as the singles. IMHO
I have one of the earlier Jeff Beck Strats with the lace sensor coil tap on the bridge and was able to get the best of both worlds here. (I can see why Robben uses a coil tap with this amp)
Other obvious things to note is the amp had to be cranked a bit louder than I would use in a band situation to find the sweet spot.
The transition from clean to OD was very transparent which was nice.
The equippment I used was a Les Paul AAA Prem Plus. Epiphone 335 copy (Which sounded the best in OD hands down)
a Beck 1998 strat and a Eric Johnson Strat and an Avatar 2X12 loaded with origional G12H- 75's
If I could get away with playing this loud I prefer this setup over the higher plates. Definiately more organic sounding.
Just my worthless opinion
ElectronAvalanche wrote:Between the Ratio and 150k there was a tone cut in the #123. The Ratio was 1M in the mentioned amp. I call Ratio the OD Master Volume.
Cheers,
DominiK
Every now and then I get visions, and now is one of those moments. I can clearly see #123 on a big island type of place... Australia!
Gil
Hi Gil,
ey mate! Did not know the amp was down under.
Maybe you can expand your vision and somehow look inside the OD Ratio/Master?
I was able to look at the schemo of amp #123 some years back. By then it had already changed owners.
So you are saying that the OD fed directly into the 1M master with no level? #123 would have a level control on the chassis. You sure your notes are correct? 150K into 100K pot w/HF trim control. Then into master?
Hi Scott,
I guess I was not quite clear enough with the "from the ccw of the 1M to 500k pot to 0.022 uF to ground" part in my posting. "ccw" would mean on the input side of the OD Master.
Look at the ODS101 schemo: 0.005 uF OD2 decoupling, into 150k, tone pot (500k, cap to ground) into 1M OD Master from there to PI.
The 500k reading of the input pot of the OD was measured by someone who I think knew what he did. I did not measure it myself.
Cheers,
Dominik
If the 500k pot was set at around 330K than the nett load on V2b would be around 250K again, since these 500K trimmer with cap network, and the RATIO 1M pot are in parallel. This is only the case if the 22nF cap is big enough of course to shunt all relevant frequencies to ground......otherwise it would only count for the higher frequencies.
What do you guys think?
Maybe you can expand your vision and somehow look inside the OD Ratio/Master?
I was able to look at the schemo of amp #123 some years back. By then it had already changed owners.
Cheers,
Dominik
Only because you asked:
The channel switching board was old style, with 5 eyelts (for the audio part) instead of 6. So that means Dumble didn't ground the OD input when in clean channel, which is definitely old style wiring. However, that doesn't necessarily mean that the OD master volume was cascaded with the overall master volume. My vision also tells me the amp had a true Deep switch wired, a 250K bass pot and a 100K middle pot. And that's pretty much all the light I can shed on the subject.
jelle wrote:If the 500k pot was set at around 330K than the nett load on V2b would be around 250K again, since these 500K trimmer with cap network, and the RATIO 1M pot are in parallel. This is only the case if the 22nF cap is big enough of course to shunt all relevant frequencies to ground......otherwise it would only count for the higher frequencies.
What do you guys think?
Jelle, it would be more like 400K... you'rer forgetting about the 150K resistor at the output of V2B. Anyway, the tone control cap on that amp is physically pretty big...
