tight bass on a Dumble - can it be done?

[TimS]

Is there any way to tighten the bass on a D-style amp without making it sound thin?

[Funkalicousgroove]

300uf caps on the first filtering stage, 100uf caps on the screens, .02 PI couplers for starters.

[TimS]

300uf caps on the first filtering stage, 100uf caps on the screens, .02 PI couplers for starters.

Would you mind describing the exact locations of those caps? I'm new to amp building and while I've got a pretty decent understanding of preamps, my knowledge of power sections is still fairly minimal.

Here are the D'Lite schematics as a reference: http://www.brownnote.net/forum/viewtopic.php?t=274

Which caps would be replaced by the values you mentioned?

Thanks.

[mlp-mx6]

300uF is the first filter (stack?) in the power supply. 100uF is the 2nd filter (post-choke, or post-BIG-resistor). PI coupling caps are the last 0.1uF guys on the end of the "preamp" board.

(The power supply is not present on the schem I looked at in your link)

[TimS]

300uF is the first filter (stack?) in the power supply. 100uF is the 2nd filter (post-choke, or post-BIG-resistor). PI coupling caps are the last 0.1uF guys on the end of the "preamp" board.

(The power supply is not present on the schem I looked at in your link)

Thanks. I had a feeling the 0.1uF caps were the couplers.

For the other two, could you please point out their locations on the D'Lite layout? http://www.brownnote.net/shared/images/ ... %20Mod.bmp

Thanks again.

[Funkalicousgroove]

All I get is a blank page on that link.

[TimS]

All I get is a blank page on that link.

I think you have to right click and select "save as" for it to work.

[BobW]

50uFs in a bassman w/stock iron, has all the bass you need, w/no mud.

[TimS]

50uFs in a bassman w/stock iron, has all the bass you need, w/no mud.

Perhaps, but I've already got the Bassman thing covered. I like the overall Dumble sound; I just wish it was a bit tighter in the bass and am wondering what I could do to get it there.

[mlp-mx6]

For the other two, could you please point out their locations on the D'Lite layout? http://www.brownnote.net/shared/images/ ... %20Mod.bmp

Thanks again.

The 2 350V 100uF become 350V 300uF. On that picture, the "bottom" 22uF 450V (the one next to the Xicon 500ohm resistor) becomes 100uF 450V.

I hope they fit! They WILL be larger than what you have, and may be larger than you have room for. That power supply board was designed for the caps that are on there.

[ampgeek]

Hey Tim,
Also consider reducing V1 cathode bypass capacitors a smidge (pins 3 and . Currently at 10 uf. Try 5uf (like on V2) to see if it gets you going in the right direction.

Dave O.

[ampgeek]

Hmmm....I guess that an 8 and a ) yields an emoticon.

Should be pins 3 and 8.

TEST:

Good luck,
Dave O.

[dogears]

Be careful about going large on the filters. It can easily make the amp very buzzy.......

[mlp-mx6]

Be careful about going large on the filters. It can easily make the amp very buzzy.......

Please note for the record - I am not recommending this, simply explaining which caps were the ones in question!

[Bob-I]

Is there any way to tighten the bass on a D-style amp without making it sound thin?

IME the bottom end on a D style amp is solid and tight if the iron is decent. It'll never be SLO tight, but it's not SLO buzzy either. If your bottom end is loose and flabby there's something wrong with the build, not the design.