97_ODS_HRM_Loop Schematic Question

[erwin_ve]

I was off-base above- the change in capacitance at high frequency is negligible (inaudible) since the Rk//Ck roll-off is way down at a couple of hundred Hz. In other words, that's where the capacitance value becomes important. The specs for max ESR in e-caps (including this one) are much higher than I measured (~5x), so perhaps other brands are closer to their upper spec limit? Here's how it plots:

I can't justify myself buying a LCR meter with freq testing like yours, I'm a hobby builder, but this begs for a test!
Is there any chance in the future you could do a test with different lytics?
It would be interesting to see if the knee frequency for Rk//Ck is affected bij the ESR/capacitance value.
There are no more freq you can test with the B&K?

[martin manning]

No, that's it. 100 and 120 Hz, for obvious reasons, plus 1k and 10k. I agree it would be interesting to see if ESR and tonal differences are correlated, but the other caps I have laying around are old and probably suspect. ESR doesn't do much by itself, just reduces gain due to local NFB. If it's substantially different then that should be audible. I recently picked up a cheap ($16) Chinese tester that seems to be ball-park close to my B&K, and it analyzes transistors and other components as well. I don't know what frequency it uses to test, but it's a fun gadget.

[norburybrook]

I'm not entirely convinced about the sonic effect of the outside foil personally so it's interesting that you found a before and after positive effect.

It may be possible that in not checking on my amps I got them the right way round by accident, although the chances are slim that they'd all be the right way.

I made one amp where I did make sure and it didn't sound any 'better' to me, so I've gone back to not bothering again I'll probably find this current build sounds rubbish now

I agree with Erwin about the high plate amps vs the low plate in the ODS from the compression/overtone thing.

I will say though that the amp is only one part of tone chasing, and the ODS isn't for everybody. Joe Bonamassa sold all his ODS amps, Eric Clapton didn't get on with his. My good friend tried every version and in the end after about 6 years went back to a plexi based amp.

Speakers have a huge sonic impact on how the amp sounds, and also the guitarist and the guitar. For me personally these last three things have a greater impact on the overal tone than any difference in caps/resistors etc. Also live the room comes into play, and if you're in a studio the mic's and engineers experience also come into play and can negate any subtle tonal changes from 'golden' components.

I'm very interested in all this component measuring and testing as like all of us I'm chasing that tone I hear in my head. Fortunately I have been able to test some of this for myself albeit not particulary scientificaly but I think it's a good conversation to keep having.


Marcus

[Matt J]

The Low plate has more headroom, high plate has more compression and more overtones.
Both are dynamic in response to the volume control on your guitar.

When you mention high plate versus low plate, are you describing only V1 or V1 and the V2 tube for overdrive as well? I only have experience with 100k 2nd gen and #124 builds so I'm a little curious.
- Matt J.

[erwin_ve]

The Low plate has more headroom, high plate has more compression and more overtones.
Both are dynamic in response to the volume control on your guitar.

When you mention high plate versus low plate, are you describing only V1 or V1 and the V2 tube for overdrive as well? I only have experience with 100k 2nd gen and #124 builds so I'm a little curious.
- Matt J.

Matt, for Both V1 and V2.

[erwin_ve]

I made one amp where I did make sure and it didn't sound any 'better' to me, so I've gone back to not bothering again I'll probably find this current build sounds rubbish now

I will say though that the amp is only one part of tone chasing, and the ODS isn't for everybody.

Speakers have a huge sonic impact on how the amp sounds, and also the guitarist and the guitar. For me personally these last three things have a greater impact on the overal tone than any difference in caps/resistors etc.

Marcus

If it sounds good it sounds good! When building your first you did it right: asking and going blind on other experienced builders. That payed off.
I went from a mediocre Ods, experimenting with parts and foil placement, lead dress, measurement etc, to a fantastic sounding Ods.
Fe. I can have snubbers on the V2 pins as low as 25pF on a #102 built without sounding harsh, all high tones are there but smooth. Imo snubbers on V2 anything higher than 330pF are bandaid for things going on that are not supposed to. Just a example.
I will never go back to building other than described. On some things it proven science and some are not proven by science(yet! ).
So I'm perfectly fine when someones questions non proven views. There are no big $ involved and easily can try for yourself and come to other conclusions.


The Ods isn't for everybody: agreed!
As far as guitars concerned: I like these amps better with brighter sounding pickups. Im interested on your views on this. Can you give a example on what you're looking for in a tele with single coils?

[norburybrook]

I only have one tele that's 'standard' with single coils. It's a maple/white blonde, black guard with pickups wound by a forum member RogB.

My other teles have P90 neck, 'lil 59 bridge , Filtertron neck, single coil middle(tele neck pickup), filtertron bridge, or humbucker/Humbucker thinline.

I generally roll the tone down when using the OD.

M

[fred.violleau]

If you go with the HRM, I would advise you tu put a ground lift on the HRM tonestack.
I played a lot with it this weekend, and the sound is more "open" and "full" when HRM is lifted (out of the equation)

Fred.

[erwin_ve]

If you go with the HRM, I would advise you tu put a ground lift on the HRM tonestack.
I played a lot with it this weekend, and the sound is more "open" and "full" when HRM is lifted (out of the equation)

Fred.

You like non hrm?

[fred.violleau]

If you go with the HRM, I would advise you tu put a ground lift on the HRM tonestack.
I played a lot with it this weekend, and the sound is more "open" and "full" when HRM is lifted (out of the equation)

Fred.

You like non hrm?

I love non HRM a lot!
There is more of everything in the sound.
More volume, more density, more musicality.

On a side note, I exposed the HRM tonestack on the front plate of my amp. So I can play with the settings. I though it would bring versatility to it. I have to play more with the HRM tonestack to see if it is a real added value. For now, I am not sure


Humble and Dumble,

Fred.

[norburybrook]

The HRM works great on the Bluesmaster, there's NOTHING lacking in that amp. Sparkly cleans, full on overdrive especially with the Boost

I've not tried the HRM on a regular ODS though.


M