need more bass

[danotron]

I have a high plate non-hrm. It lacks bass. I have been playing with it for a while now and can't get any bottom end. I have increased the clean channel bi-pass cap's from 5uF to 25uF and there is no difference. I bi-passed the tone stack but nothing o bass is added just volume. What could the problem be? Are there any tweaks to add more bass?

[David Root]

Sounds like something is wrong somewhere, going from 5 to 25uF should make a noticeable difference.

What value is the bass tone pot? Maybe you used a 25K pot instead of a 250K by mistake?

[briane]

yep - somethings wrong there - tons of bass in those amps -

unless you play a bass...should be no need to change caps - and change in tone is big.

[aflynt]

If I could give you some of mine I would. I rarely get the bass knob above 2 on my latest #102 clone. The bass control never gets above 3 on my other one. With the bass on 5 my new one with the MM Tweed Twin OT will just about knock you over. I was actually planning on wiring something in there the limit the range of the bass pot.

Anyway... I'd third the notion of something not being quite right.

-Aaron

[ToneMerc]

I'm curious, is it a 6V6 amp?

TM

[Structo]

If I could give you some of mine I would. I rarely get the bass knob above 2 on my latest #102 clone. The bass control never gets above 3 on my other one.
Anyway... I'd third the notion of something not being quite right.

-Aaron

Same here, although I do have a large 2 x 12 with two EVM 12L's which sort of sits in the corner of the room, but there is other stuff back in the corner.

I rarely get my ODS above 3 on bass.

[crbowman]

Check the value of the cap on your bass pot.
You might even try removing it. That should get you plenty of bass.

[cornel moldovan]

Try to replace the output transformer with a bigger one. Do not change values in the schematic .. increased core section will give you more lows... [/b]

[danotron]

the bass pot is 500k. I removed the cap across the bass pot and there was no change. I put a temporary switch in there to switch between cap and no cap but could not hear any difference.

The amp is a two 6L6 amp and the tone stack is: Bass: 500k/.1uF, Mid is 100K/.047uF, treble is: 250K/330pF. Like a Dlite.

I changed the slope resistor to 68K with minimal change in tone.

I bypassed the hole tone stack by disconnecting the slope resistor and it thinned out allot.

The OT is a Hammond 1750M. Could it be the problem?

I'm running it into a G12-65 single 12 cab. I run other amps in this cabinet so I know its ok.

Any suggestions on what I could try to find the problem?

[Structo]

You can also experiment with the 10K resistor value on the bass pot.

Smaller sends more bass to ground but it mainly affects the lower mids.

You can also increase the value of the PI output caps.

If you already have .1uF there, then I would leave those alone.

Do you have the capability to measure cap values?

Double check all your preamp values, it has happened to me where I put the wrong part in the wrong place.

[M Fowler]

I had the same trouble with the Dlite 16x8x2 version and added .001 cap across 500KA bass pot. Change mid cap to .01 from .05, slope 150k, 330pf treble cap.

The amp is still bright but not as much. All other components were correct values so not sure why the amp would be a lot brighter then other people's amps.

Mark

[bluesfendermanblues]

Agree with that Alpha pots sounds as good as any, but they are prone to malfunction if you heat them a little too much....so, if you use alpha pots, you could have a faulty basspot. They don't take much soldering heat IME.

Prior to changing the bass pot, try the old chopstick test to make sure you don't have a loose connection in the tone section pots.

[grtamp]

For my experienced , Hammond trafos are not the Top for this type of amp!, but I could be wrong.

[tubedogsmith]

do you have a diagram of how you wired the pots. also, a 150k slope resistor should be a noticeable bump over 68k.

[briane]

I had a fault bass pot once did same thing - yes too much heat when I soldered the buss bar cause it tested good before.

For my experienced , Hammond trafos are not the Top for this type of amp!, but I could be wrong.

nope - your right - they sound sterile with no warmth or clarity in these builds.

compare to a triode 470s - wear diapers!@