non hrm bass heavy

[ayan]

it is the 101 non hrm, all component values as per the schematic, yes it could be the speakers and/or the studio he has tried the amp in, I have not been present when he has tried it, as this is my 1st build I posted because I thought it may be a characteristic of the amp, I will offer to "voice" the amp how he wants it, maybe swop the 0.1 cap in the tone stack to .047 or .022, I may also try reducing the values of the coupling caps,

forgot to mention,
it is; 220k/3k3/5uf
150k/2k2/5uf
220k/3k3/5uf
150k/2k2/5uf
skyliner eq, 100w, 4 x 6l6gc

I have tried this configuration a few times and never really liked it -- although some fabled amps are built this way. I much prefer the 100K/1.5K version, with 10uF or higher bypass caps on the clean and 5uF on the dirty stages. One thing you could try with your amp, as is, would be to lower the 2nd clean cathode bypass cap to 1uF... or go with a high-ish brightness cap on the master volume pot (47pF, 68pF).

Gil

[Structo]

Another trick is to to run two wires from the right two lugs (when viewed from the rear) on the bass pot that are normally jumpered.
Take a wire from each lug and connect them to the PAB relay so when the amp is not in PAB mode the two are connected, but when the PAB relay is engaged that jumper is broken.
So the two wires are connected to the normally closed contacts of the relay.
This will make the bass not so heavy in PAB mode.

Now if the amp has just too much bass all the time you can experiment with the bypass caps.
If both channels have too much, you may want to try a 1uf cap on either V1b.

If it is only too heavy when in overdrive, try a 1uf in V2b.

I may add a HRM board to my amp down the road a ways.
That way you can adjust the tone controls on the front panel for you clean tone, but then fine tune your OD tones with the HRM board.

[dogears]

Breaking the jumper in PAB mode adds bass!

Just sayin'

Another trick is to to run two wires from the right two lugs (when viewed from the rear) on the bass pot that are normally jumpered.
Take a wire from each lug and connect them to the PAB relay so when the amp is not in PAB mode the two are connected, but when the PAB relay is engaged that jumper is broken.
So the two wires are connected to the normally closed contacts of the relay.
This will make the bass not so heavy in PAB mode.

Now if the amp has just too much bass all the time you can experiment with the bypass caps.
If both channels have too much, you may want to try a 1uf cap on either V1b.

If it is only too heavy when in overdrive, try a 1uf in V2b.

I may add a HRM board to my amp down the road a ways.
That way you can adjust the tone controls on the front panel for you clean tone, but then fine tune your OD tones with the HRM board.

[Tonegeek]

On my LOW PLATE non-HRM Skyline I had too much low end, epecially when using 2X G1265 speakers. I tried everything but changing the bypass caps and what worked was changing the PI input from .02 to .01. This was the best solution in my case. Still the bass control ends up pretty low. My experience with dropping the .05 coupler from V1b was that yes it lowered the bass, but it also cut into some low mids in a negative way. Turning up the bass control did not compensate for those missing frequencies so the coupler went back to .05.

[Structo]

Breaking the jumper in PAB mode adds bass!

Just sayin'

Really?

I thought the whole idea was to decrease bass when the PAB was engaged?
In fact I thought it was you that said when PAB was engaged you wanted that jumper disconnected?

This is a post I copied to my notes that you made a while back:

The bass pot needs to have the 1st and 2nd lugs connected, via relay, when in normal mode. This connection is broken with PAB on. The practice of not connecting them was an error. It ruins the tone of the amp IMO (unless you are looking for that one specific thin tone and nothing else) and I have played them that way. If the amp is too bassy, then you should try reducing bass via one of the several tried and true ways. Not by messing up the the stack operation. So, for me, bass mod is not the right term. The incorrect way would be the mod. Connected is the correct way. There is no middle ground or gray area. Wire the stack the way Dumble did. There are no valid arguments for doing anything different. As I said, if you want to reduce bass content, you can reduce the CL2 coupler, lower plate loads, change bypass caps, etc.....

[JD0x0]

looking at the layout the treble pot is a 250K B try changing it to a linear you'll get more treble and you'll lose a very small amount of bass. it could balance it out nicely for you and it's a very cheap easy upgrade.

I always use linear treble pots on my d-style amps

[bluesfendermanblues]

looking at the layout the treble pot is a 250K B try changing it to a linear you'll get more treble and you'll lose a very small amount of bass.

Hmm, don't quite agree with you on that one,

250k is 250k. Log vs lin is only a matter of where the knob has to be on the treble scale in order to get a certain ohmic value.

[dogears]

Tom, breaking the jumper increases the resistance to ground to the full value of the pot. So, if you set the bass at about 200K when not in PAB, you increase the resistance to ground all the way to 500K. PAB for me loses a ton of bottom. It needs all the help it can get which is why I always break the jumper.

Breaking the jumper in PAB mode adds bass!

Just sayin'

Really?

I thought the whole idea was to decrease bass when the PAB was engaged?
In fact I thought it was you that said when PAB was engaged you wanted that jumper disconnected?

This is a post I copied to my notes that you made a while back:

The bass pot needs to have the 1st and 2nd lugs connected, via relay, when in normal mode. This connection is broken with PAB on. The practice of not connecting them was an error. It ruins the tone of the amp IMO (unless you are looking for that one specific thin tone and nothing else) and I have played them that way. If the amp is too bassy, then you should try reducing bass via one of the several tried and true ways. Not by messing up the the stack operation. So, for me, bass mod is not the right term. The incorrect way would be the mod. Connected is the correct way. There is no middle ground or gray area. Wire the stack the way Dumble did. There are no valid arguments for doing anything different. As I said, if you want to reduce bass content, you can reduce the CL2 coupler, lower plate loads, change bypass caps, etc.....

[dogears]

Tom, breaking the jumper increases the resistance to ground to the full value of the pot. So, if you set the bass at about 200K when not in PAB, you increase the resistance to ground all the way to 500K. PAB for me loses a ton of bottom. It needs all the help it can get which is why I always break the jumper. Breaking it when not in PAB kills the bass in a bad way for me.

Breaking the jumper in PAB mode adds bass!

Just sayin'

Really?

I thought the whole idea was to decrease bass when the PAB was engaged?
In fact I thought it was you that said when PAB was engaged you wanted that jumper disconnected?

This is a post I copied to my notes that you made a while back:

The bass pot needs to have the 1st and 2nd lugs connected, via relay, when in normal mode. This connection is broken with PAB on. The practice of not connecting them was an error. It ruins the tone of the amp IMO (unless you are looking for that one specific thin tone and nothing else) and I have played them that way. If the amp is too bassy, then you should try reducing bass via one of the several tried and true ways. Not by messing up the the stack operation. So, for me, bass mod is not the right term. The incorrect way would be the mod. Connected is the correct way. There is no middle ground or gray area. Wire the stack the way Dumble did. There are no valid arguments for doing anything different. As I said, if you want to reduce bass content, you can reduce the CL2 coupler, lower plate loads, change bypass caps, etc.....