heisthl wrote:Clips sound good - making the assumption this is nonHRM I have a small suggestion, in the first clip you can hear a little buzzy distortion when low notes are played that you may not like - try putting the OD entrance mod from the HiGain schematics using the 10M to ground and a .01 cap before the resister feeding the OD1 trimpot. This won't change the sound much but should alleviate some of the lownote buzziness. Sorry if this seems too "nitpicky" The amp sounds really good.
Hi heisthl,
I did put a 10M to ground + 0.01 on the OD entrance. The result was very pleasing More clear lower strings. Is it so that bigger value cap blocks away more bass OR vice versa ? I might try a 0.047 in there also
I also did what dogears suggested for me on the other thread. 'Try a touch more negative feedback to smooth things out'. I put 2k in place of 4k7 and wired a 5k pot as a variable resistor and liked the different positions so much I did put the pot on the place of the 8ohm speaker jack
The smaller the cap the harder it is for the bass to "squeeze" through - the 10M gives it a place to go instead. For a whole different sound try a .001 - I had a hard time picking a favorite so on the last project I wired a on-off-on toggle to get .001,.01(+ the .001) and direct connect (still with the 10M in circuit).
heisthl wrote:The smaller the cap the harder it is for the bass to "squeeze" through - the 10M gives it a place to go instead. For a whole different sound try a .001 - I had a hard time picking a favorite so on the last project I wired a on-off-on toggle to get .001,.01(+ the .001) and direct connect (still with the 10M in circuit).
Ok, thanks for the tip. I'll connect my 'capasitor box' in there. It has values from picos to microfarads. I think the voltages are reasonable low on that spot..
I never heard of that bass cut mod in front of the OD. Anyone tried to make it switchable?... With this mod OD entrance would be .047uF coupling cap, 10M to ground, another .047uF and to the low gain OD entrance network. Did I get this right, at all?
Dogears said:
Ignore the bass cut mod.... That is not what this is. It is only a simulated clean master load for the OD since the bright cap on the clean master is a treble bleed when the OD is on. By floating the clean master ground (when the OD is on with a 10M) you don't have the bleed. The simulation is to add a 1M to ground from the OD input side of the cap to ground.
Been trying to get a handle on this part of the circuit but I'm confused... I thought it was to avoid the treble bleed with the OD on. With 10M going to ground between the two caps, how much different is that, sound-wise, than just putting the coupling cap and the second cap (.01 or whatever) in series? Or am I picturing the 10M/cap in the wrong place? Or maybe just totally lost...
This whole bit is regarding HRM amps with seperate masters. So it has nothing to do with the 80s circuit Mat has.
Fwiw, I don't care for trimming too much bass before the OD. It may be smoother in a way, but it is souless (for me) and lacks the beefy growl I hear in Dumbles. These guys are simply adding a series cap before the 220k resistor that precedes the 100k trimmer.
Chris333 wrote:From page 2 of the ODS 101 schematic thread:
Fabiomayo said:
I never heard of that bass cut mod in front of the OD. Anyone tried to make it switchable?... With this mod OD entrance would be .047uF coupling cap, 10M to ground, another .047uF and to the low gain OD entrance network. Did I get this right, at all?
Dogears said:
Ignore the bass cut mod.... That is not what this is. It is only a simulated clean master load for the OD since the bright cap on the clean master is a treble bleed when the OD is on. By floating the clean master ground (when the OD is on with a 10M) you don't have the bleed. The simulation is to add a 1M to ground from the OD input side of the cap to ground.
Been trying to get a handle on this part of the circuit but I'm confused... I thought it was to avoid the treble bleed with the OD on. With 10M going to ground between the two caps, how much different is that, sound-wise, than just putting the coupling cap and the second cap (.01 or whatever) in series? Or am I picturing the 10M/cap in the wrong place? Or maybe just totally lost...
keithrick wrote:Mat. Awesome clips! I agree that these are the best I've heard.
Did you end up using the Caps and Resistors I sent? Again, great job!
Keith
Hi keithrick
Wow! Thank You for Your compliment
Yes I did put the caps and resistors in that You sent me (I e-mailed You on 15.8.) and they have helped alot. Big thanks for them again It is so nice to have this kind of a community of gentlemen to help us who do not have a direct access for some parts Much appreciated !
I've made so many changes to my clone that it begins to look like a war zone But the most important -the sound- is very sweet IMHO. Maybe it is just me but I always want to dig deeper for THE tone
I just bought a Epiphone LP copy and now I've stripped it down of all possible parts for the mods I'm going to do for it (opening the pu cavity to take P90 in it and winding couple of PAF's + remaking the whole electronics + repairing a 'small' crack on the topwood that my wife got there when hoovering ).
Next I will try the different resistor values in the NFB area as here has been suggested. And I will again try A/B the 'bassmuddinessremoval'-mod I did to my clone that maybe shouldnt be there if I understand dogears comment in a right way (upper). He has been giving a great advices to me so I believe I'd better to check again.
I also have to tame my Express clone a bit of its tightness. Will try Xicons in it... but this is not the place to talk about it.
More clear lower strings. Is it so that bigger value cap blocks away more bass OR vice versa ? I might try a 0.047 in there also 
I agree that these are the best I've heard. 
But the most important -the sound- is very sweet IMHO. Maybe it is just me but I always want to dig deeper for THE tone 