Clips of 100W High Plate Non HRM.

[Dr d]

Nice work, Paul, and great sounds too!! Funny how the tinkering we find ourselves doing almost always takes us back to where we started in the first place.!!! What led you to reducing the grid resistor on V2 and may I ask what iron and valves you used? Cheers, A.

[Guitarman18]

LPSGME wrote:

However I noticed that feedback loop on V1B is not on the 101 schematic - least not the one I am seeing. Neither are the V2 snubbers in the OD.

As Tom said, this one is a Non HRM. I think the LNFB helps the OD tone on these 100W amps, but I have a 40W which lacks girth by comparison and the LNFB in that amp makes it sound too constrained, particularly on the cleans. I put mine on a switch, on that amp.

Cheers,

Paul.

[Guitarman18]

Dr d wrote:

Nice work, Paul, and great sounds too!! Funny how the tinkering we find ourselves doing almost always takes us back to where we started in the first place.!!! What led you to reducing the grid resistor on V2 and may I ask what iron and valves you used? Cheers, A.

Thanks A,

The standard value resistor fed from the .005uf cap on OD2 plate is often 150k but I increased mine to 180K. For me it gave the tone more focus, if I remember correctly. I did it because I had read some discussions on it, in some of the earlier posts. I think dogears had mentioned that he had done it on one of his amps. I might be wrong.

I had Heyboer make some iron for me. I went with 238V on my primaries, because here in my house the supply is around 245V most days. (country side ), and yet most towns and cities are about 230v (regulation), so I tried to hedge my bets, so that I could get more consistent voltages. I really should use a power conditioner, but as with everything, it's just another item on my wish list!


Valve wise, I've got Tung Sol short bottle 6L6's biased at 35ma. 12AX7's are JJ's and in the PI I have a balanced Jan Phillips. All things that I'd seen posts on.

Hope this helps.

Cheers,

Paul.

[dogears]

The standard grid resistor is always (as I have seen on non HRM) a 180K on OD2. This is on the tag strip to tube socket. HRM can be either 150K or 180K. I have seen both.

The resistor fed from the .005uf cap on OD2 plate is either 150k or 180k. I have seen both. Mostly 150k.

Dr d wrote:

Nice work, Paul, and great sounds too!! Funny how the tinkering we find ourselves doing almost always takes us back to where we started in the first place.!!! What led you to reducing the grid resistor on V2 and may I ask what iron and valves you used? Cheers, A.

Thanks A,

The standard value grid resistor on V2b is often 150K and I increased mine to 180K. For me it gave the tone more focus, if I remember correctly. I did it because I had read some discussions on it, in some of the earlier posts. I think dogears had mentioned that he had done it on one of his amps. I might be wrong.

I had Heyboer make some iron for me. I went with 238V on my primaries, because here in my house the supply is around 245V most days. (country side ), and yet most towns and cities are about 230v (regulation), so I tried to hedge my bets, so that I could get more consistent voltages. I really should use a power conditioner, but as with everything, it's just another item on my wish list!


Valve wise, I've got Tung Sol short bottle 6L6's biased at 35ma. 12AX7's are JJ's and in the PI I have a balanced Jan Phillips. All things that I'd seen posts on.

Hope this helps.

Cheers,

Paul.

[Guitarman18]

dogears wrote:

The resistor fed from the .005uf cap on OD2 plate is either 150k or 180k. I have seen both. Mostly 150k.

Sorry guys, I meant the resistor from the .005uF cap is 180K on mine.

I'll edit that in my original post.

Thanks Scott, for pointing that out.

Cheers,

Paul.

[Structo]

Ha!
I just recently changed that to 150k from 180k.

I wanted just a smidgen more highs there.

On goes the battle.
Some days I think man, that sounds pretty good, then someone will come along like Paul did and blow it out of the water.

Oh well, it certainly keeps it interesting.

I wonder if many of the guys here that build there own amps do that?
Be satisfied for a period of time then decide it has too much of this or too little of that?

I don't think my amp sounds bad, just different.

most likely my hands.....

[CHIP]

Paul,
Great build, fantastic tone. I really like Clip 1.
I was wondering while looking at the ODS 101 non HRM schematic, if yours has the 250ka or 100kl mid pot with the .01 cap changed to .05 as per the early 80's footnote on the schematic?

[Guitarman18]

Tom wrote:

I wonder if many of the guys here that build there own amps do that?
Be satisfied for a period of time then decide it has too much of this or too little of that?

That is exactly how it is for me. The number of times I have thought, 'If only I had bought a Bludo', I would probably have had change to spare!

Having said that, I don't think I would be happy with a production amp that I felt I shouldn't tweak. I had an original 1965 Deluxe reverb that sounded great, but I always wanted to change things about. Luckily I resisted the temptation and sold it for twice as much as I'd paid for it.

Cheers,

Paul.

[Guitarman18]

CHIP wrote:

Paul,
Great build, fantastic tone. I really like Clip 1.
I was wondering while looking at the ODS 101 non HRM schematic, if yours has the 250ka or 100kl mid pot with the .01 cap changed to .05 as per the early 80's footnote on the schematic?

Thanks CHIP, I have 250KA mid w/ .01 (ie. Skyliner stack).


Cheers,

Paul.

[Structo]

Yeah that took me a while to understand too.
I think the skyline stack is defined by having the 250k-A mid pot and .01uF mid cap.

Somebody said one time it was because the wave form from that tone stack looked like a city skyline. Not sure if that is true but it sounds good.