Structo wrote:I believe that Gil advises putting it on the level pot.
But he puts it on a small daughter board at the 180K resistor that goes to the level pot input.
Not really. "My" treble bleed goes on the RATIO control, on the Lead Master Volume, etc. That is, it ties to the 150K output resistor at V2B. The further down the road you put the treble bleed, the richer the harmonic content of the tone IMNSHO.
Gil
OK, I re-read your correction but I am still thoroughly confused.
Are we talking about #124 topology?
You say it goes on the Ratio pot, which is tied to the 100K pin 6 of V2.
Then you say the "on the lead master volume", which is the level pot,
150K pin 1 of V2.
Then there is what are we calling V1a and V1b. Since HAD oriented the tubes with the b side being staged first.......
RATIO = LEAD MASTER Pot, tied to a 150K (or in some amps 180K) output resistor for the ENTIRE OD channel.
LEVEL = First OD pot, dials in the amount of dirt when in OD mode.
I hope there aren't any questions after this.
Hi guys...you are bidding on a Dumble Overdrive Special Skyliner EQ in mint condition, The Holly Grail of Guitar Amplification, used by renown guitarist all over the world, I have no words to describe the sound of this amplifier.
He doesn't say it is a HRM amp.
Later he defines it but doesn't claim this amp has it.
In some newer models (1990s to present), the overdrive stages are followed by a passive tonestack (treble , middle and bass), which is adjustable using trimmer potentiometers inside the amplifier. This is known as the "Hot Rubber Monkey" (HRM) modification (these amplifiers are voiced for the overdrive channel to be used with the preamplifier boost engaged). Most players use three tones: clean, clean with boost on, and overdrive with boost on.
The "Skyliner" EQ refers to a newer (mid-1980s to present) way of voicing the tonestack. It is said to provide a better clean tone than the earlier voicing of the tonestack. Some lower serial number amps have been retrofitted with this EQ
talbany wrote:You can shunt highs (cap to ground) anywhere inside the overdrive circuit you want...Non HRM are usually the snubbers pins..1/3--- 6/8 not the same as the treble bleed but does help with oscillation and tames the highs a bit..
Putting the treble bleed at the ratio on the Ceriatone after the last gain stage giving the circuit it's greatest effect...IMHO..(Same place where Dumble did the tone shaping for his HRM's)... Gill came up with it so he may have another reason why he put it there...To me it's pretty obvious...
BTW.. Ratio and Level are isolated overdrive only in your amp...
Tony VVT
talbany,
Alexander came up with it, called it "taper" and - as far as I remember - it's from the connection of the 150K(e.g.) resistor and the OD Volume ('ratio') to ground.
He used different values here and then (one of the early eighties: 500K trim pot and 22nF). It works great (IMHO) to adjust just the amount of high end in the OD sound you like best.
Alexander came up with it, called it "taper" and - as far as I remember - it's from the connection of the 150K(e.g.) resistor and the OD Volume ('ratio') to ground.
He used different values here and then (one of the early eighties: 500K trim pot and 22nF). It works great (IMHO) to adjust just the amount of high end in the OD sound you like best.
Cheers and all the best
Max
Hey Max
Thanks for clarifying....I remember you mentioning that in an earlier post..may have been in reference to Gregor's amp..not sure.... Anyway thanks for the in depth description..
For me personally I prefer the higher plate non HRM's and to my ears don't need any treble bleed.. (the snubbers do fine)... I know the 100k plate amps can be a bit brighter and needing the taper.. Thanks Again!!
I have installed the treble bleed at the Ratio pot on my Ceriatone OTS (non-hrm), and it works well, yet it seems to be taking out a larger portion of the frequency spectrum than I would like. I am currently using a 1000pF to 45K ohms to ground arrangement. If I wanted to knock out just the very highest, harsh frequencies, how would I change the components?
Am I right in saying that the value of the resistor changes how much of the highs you remove and the value of the cap changes which specific frequencies you remove? Would lowering the value of the cap to 470pF target higher frequencies than the 1000pF or lower frequencys? Sorry to be such a noob, and many thanks as always.
For the treble bleed I installed, I have a 1000pF cap attached to the right hand lug on the Ratio pot (the lug with the "B" next to it) and one end of a 45K resistor attached to the cap and the other end of the resistor to ground.
Most interesting thing I'm finding is in this thread, is rolling off treble.
Correct me if I'm wrong. Doesn't the entrance bass roll off that effect the OD tone more, are we heading toward the "tube screamer" approach for od issues.
I have the Ceriatone and find treble side of the amp under control with all my guitars, it's the massive bass boost that the rock mode provides that screws with the overall balance of the clean/od parts of this amp.
Last edited by nickm57 on Thu May 07, 2009 1:17 pm, edited 1 time in total.
