Treble control tweaks.. follow-up

[Bob-I]

Tons of great information going in the the last thread about treble control effectiveness. I decided to post this to describe the changes tried, discarded and accepted.

1) Pot taper, Thx but it doesn't affect the overall amount, just where it comes on. Scrapped
2) 100K slope, Again thx, but it acrually had the opposite effect, scrapped
3) Modify to a full Bluesmaster. This will take some time, but I decided to make changes a few at a time and listen

a) Rp and Rk moved from 220/3.3 and 150/2.2 to 120/1.8 and 150/2.2. Overall change, brighter, more snappy response, tone controls have the same effectivness.

b) Swapped out a 25KB for the 250KB mid pot, swapped out .022's for rthe .1 and .01 in the skyline TS. I left the PAB wired the same, disconnect the bass control wiper and treble pot. Seems to work fine. Overall range of the tone controls is completely different.

I'll need some time with these changes to see how I like it.

Next, tackle the PI.

[David Root]

Bob-I, your stage gain reductions, were they in the clean or OD section?

I'm just starting on a BM HRM and using Heistl's schematic, which is 220K/3K3 & 150/2K2 on clean and 180K/2K7 & 120K/1K8 on OD.

Since the lower gain pairs are brighter, from that point of view wouldn't it make sense to use higher gain on the OD where you don't want too much high end? OTOH, the extra gain might generate some nasties too.

Just have to try 'em and see I guess. Let us know how it works out.

[jelle]

Bob,

Sounds like you suffer from Skyline-itis. Some people do not like tis tonestack. Have you wired the tonestack to Bluesmaster specs? That might be the ticket for you. Also, you may want to shange the 220K/500P V1B grif stopper network to 56K. That will make it less bright.

Just an idea.

[Bob-I]

Bob-I, your stage gain reductions, were they in the clean or OD section?

I'm just starting on a BM HRM and using Heistl's schematic, which is 220K/3K3 & 150/2K2 on clean and 180K/2K7 & 120K/1K8 on OD.

V1. I'm not using any specific schematic, but reading posts and looking at all the BM schems posted. I decided to try a few things and this made since to me, brighten up the clean side.

Since the lower gain pairs are brighter, from that point of view wouldn't it make sense to use higher gain on the OD where you don't want too much high end? OTOH, the extra gain might generate some nasties too.

Just have to try 'em and see I guess. Let us know how it works out.

We're in agreement both on the evaluation of gain/brightness/location and the Nike strategy, just do it.

[Structo]

Bob,

Sounds like you suffer from Skyline-itis. Some people do not like tis tonestack. Have you wired the tonestack to Bluesmaster specs? That might be the ticket for you. Also, you may want to change the 220K/500P V1B grid stopper network to 56K. That will make it less bright.

Just an idea.

Is that a typo Jelle?

Do you mean change the resistor to 56K or change the cap to 56pf?

[Bob-I]

Bob,

Sounds like you suffer from Skyline-itis. Some people do not like tis tonestack. Have you wired the tonestack to Bluesmaster specs? That might be the ticket for you. Also, you may want to shange the 220K/500P V1B grif stopper network to 56K. That will make it less bright.

Just an idea.

Yes, I did BM spec tone stack except for the PAB which I left unchanged.

[ChrisM]

Bob,

Sounds like you suffer from Skyline-itis. Some people do not like tis tonestack. Have you wired the tonestack to Bluesmaster specs? That might be the ticket for you. Also, you may want to change the 220K/500P V1B grid stopper network to 56K. That will make it less bright.

Just an idea.

Is that a typo Jelle?

Do you mean change the resistor to 56K or change the cap to 56pf?

I thought the 70's ODS' used 56K there.

[Structo]

You are right Chris, I didn't know he was referring to the 70's ODS.

[jelle]

yes that was the idea. Bob, keep us updated.

jelle

[Bob-I]

This amp is now a BM.

CL1 = 150K/2.2k
CL2 = 120K/1.8k
TS is 250pF + .001uF for mid boost, .022/.022, 250K, 25k, 500k
PI = 520 / 10k with a 47pF snubber (SM) across the plates
NFB = 100k
Output couplers .022uF

Presence = 4.7k / .1uf / 25K
I left OD 1/2 and PAB unchanged from the ODS101-HRM schematic.

In my little room with a 2x12 with WGS V30 and Brittish Lead, it sounds good, very different than the ODS it was and yes, the treble control is much more effective. I haven't plugged in the EVM12L/Thiele or the D-ulator, most likely I'll do that tomorrow night at the open mike night where I play in the house band.

The really cool thing about playing the open mike night is being able to test out my builds. A typical night maybe 5-6 guys will plug into my amp (under my careful supervision). Funny that sometimes guys will bring really cheezy multi effects and plug them into a D-Clone

Funny that the treble control was my concern and I ended up reworking the entire amp