non hrm bass heavy

gazza · Post by **gazza** » Wed Nov 25, 2009 9:50 am

just built a non hrm, while I am happy with the amp the guy I built it for thinks it is bass heavy, has anyone noted similar results, any thoughts on trimming the bass, all component values are currently stock.

j-po · Post by **j-po** » Wed Nov 25, 2009 11:09 am

Maybe the coupling cap after the 2nd stage?

ChrisM · Post by **ChrisM** » Wed Nov 25, 2009 1:23 pm

gazza wrote:just built a non hrm, while I am happy with the amp the guy I built it for thinks it is bass heavy, has anyone noted similar results, any thoughts on trimming the bass, all component values are currently stock.

Currently stock meaning?

mlp-mx6 · Post by **mlp-mx6** » Wed Nov 25, 2009 1:29 pm

May we assume you built the ODS-101 non-HRM?

Also, what speaker/cab is your guy using?

Structo · Post by **Structo** » Wed Nov 25, 2009 2:58 pm

Yes we need more details about the amp but in my D'Lite when I first built it I had too much bass as well.
Try 5 or 4.7uf 25v bypass caps on V1 and V2 first.

The OD entrance mod helps as well.

wjdunham · Post by **wjdunham** » Wed Nov 25, 2009 4:04 pm

I though my non-hrm was too bass heavy (with EVM12-L speakers) until I took it out of my small office where it was being built and played with the band. It turned out to be very balanced in anything other than a small room. There's a big difference between "bass heavy" and "flabby and farty" bass. I'd just turn the bass down if it's a small room, rather than mess with the circuit if it's not flabby.
Bill

Structo · Post by **Structo** » Wed Nov 25, 2009 5:07 pm

That is true.

My amp really hasn't been played out side of the spar bedroom where it lives.

The speaker cab is also on the floor about a foot from a wall which is going to affect the bass as well.

From what I can gather, a often times we think an amp is too trebly in a smaller room but when taken out to play a gig it will cut through the mix and sound good.

So I don't try to tame the highs too much.

All you have to do is put your ears down so you are in the beam to see how much treble there actually is.
If you are standing it is easy to think the amp doesn't have much treble.

I also agree about the bass. I like it pretty tight and the EVM 12L's can do that well.
I was playing my 5 string bass through them the other day and they sounded pretty badass.

JD0x0 · Post by **JD0x0** » Wed Nov 25, 2009 5:13 pm

I think we all like tight bottom end

jaysg · Post by **jaysg** » Wed Nov 25, 2009 6:01 pm

Skyliner?

Structo · Post by **Structo** » Wed Nov 25, 2009 7:32 pm

Me?

I tried the .01uf mid cap but didn't like it so reverted it back to .05uf.
I did keep the 250KA mid pot though. It did have a 100KB.

gazza · Post by **gazza** » Wed Nov 25, 2009 7:32 pm

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.

JD0x0 · Post by **JD0x0** » Wed Nov 25, 2009 7:37 pm

Never thought any D amps were too bass heavy. Maybe he's mistaking bass for lower mids/mids which ODS's are known for.

Easy solution, up the value of the slope resistor to 150K if it's not already. it will take out some lows and mids

gazza · Post by **gazza** » Wed Nov 25, 2009 7:40 pm

[quote="gazza"]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

Bob-I · Post by **Bob-I** » Thu Nov 26, 2009 8:37 am

You're on the right track with the bypass caps. If both OD and clean are bass heavy swap V1b with a 1uF, if just hte OD V2b.

Also, another very obvious answer, turn the knob labeled bass down

. Some of the speakers I've tried need to bass to go almost to 0 to get a decent balance. One guy who played through my amp at an open mike night, plugged in and turned all tones to 10, then complained it was too bass heavy

. I tweaked the eq and he said "I never thought of THAT". No one ever said it takes brains to play guitar.

marcos · Post by **marcos** » Thu Nov 26, 2009 9:29 am

Hi guys,
I see several people fighting too much low end with ODS type amps, especially with the skyliner eq.One obvious solution is to reduce the V1b coupling cap.The 50 nF value on many original Dumbles is really big, not really necessary IMHO.I would recommend 22 nF here, very good all around.In combination with the OD entrance it cuts some bass in OD mode, still plenty of bass in clean mode.I also like 10 nF as V2b coupler

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