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Hi Y'all:

I want to build my own subwoofer amp. Does anyone have a circuit? (SS is ok Yellow_Light_Colorz_PDT_09 ) I can deal with the actual amplifier section no problem. And, I can workout a selectable circuit for the LPF, but I'm curious how the commercial guys do variable LPF. Also what is the best way to attenuate the main amp speaker output and sum the stereo to mono for the subwoofer amp? Any help steering me in the right direction will be appreciated. Thanks!

Mike

SS? I have schematics for either a KGB or a Stasi .... Yellow_Light_Colorz_PDT_09

Sorry bout that. Check the Branch Letters from Mapletree Audio Design. There are some designs for both a filter (tube) and a subwoof-amp. That is, if you are lazy like me and want to pick a simple ready-made design.

http://hollowstate.netfirms.com/branches.htm

Hi Magnus,

Thanks for the lead. I see how the SW input is summed and attenuated, simple. LPF for the SW must be in the SW amp. I am looking for a variable LPF if possible. Your schematic for the KGB should have such. Any way to post it or PM a scan?

BTW I like Dr. Peppard's Thingy System. Good way to make use of all those extra tube amps!! Yellow_Light_Colorz_PDT_05

Mike

I think the "KGB" was a play on woords, rather than an actual circuit design Yellow_Light_Colorz_PDT_02

I'm not all that much into the deeper octaves and seismic wave generating "thump", but I did pick up a pair of the Dayton 10 inch, 100 Watt powered subs, back wghen they were on sale a few years ago.

http://www.bottlehead.com/loosep/S.E.Xy%20speakers.html

These are the same subs as noted on Doc Bottlehead's "SEXY speakers" which used Fostex FE-166Es in 0.25 cu foot sealed boxes, and then the subs to cover the low freqs, he suggested using one for each channel, as they were serving as powered woofers rather than "subs"" in his application. THese have individual level and "crossover" controls, and a choice of line level or speaker-level inputs. It's best not to use the built in "high pass" filters for the main speakers.

I ended up using those for TV and DVD usage, but they did sound pretty good for music applications. They don't deliver the 9.5 Richter Scale sonic booms that a 1000 watt, 15 inch powered sub will, buut then they are less likely to crack the foundations Yellow_Light_Colorz_PDT_04

Subs are one application where using Solid State (or Soiled State) is not a "sin" as the SS circuitry really does work better at the low end of the audio spectrum, and generating relatively high power levels is not too demanding.


/ed B[/i]

Ever check out the TDA7294 chip? It is capable of 100W and is supposed to be "noiseless".

http://st.com/stonline/products/literat ... da7294.pdf

Jeff Rowland allegedly uses them in his amps.

A pretty simple and dirt cheap SW solution might be 2 of these chips and an srpp preamp module (which can be gotten for about ~$35 on ebay).

These chips can be bridged.

kheper wrote:Ever check out the TDA7294 chip? It is capable of 100W and is supposed to be "noiseless".

http://st.com/stonline/products/literat ... da7294.pdf

Jeff Rowland allegedly uses them in his amps.

A pretty simple and dirt cheap SW solution might be 2 of these chips and an srpp preamp module (which can be gotten for about ~$35 on ebay).

These chips can be bridged.

Can the TDA7293 be used in the same way?

(I think I bought some of these awhile back & squirrelled them away.)

spydertune wrote:

kheper wrote:Ever check out the TDA7294 chip? It is capable of 100W and is supposed to be "noiseless".

http://st.com/stonline/products/literat ... da7294.pdf

Jeff Rowland allegedly uses them in his amps.

A pretty simple and dirt cheap SW solution might be 2 of these chips and an srpp preamp module (which can be gotten for about ~$35 on ebay).

These chips can be bridged.

Can the TDA7293 be used in the same way?

(I think I bought some of these awhile back & squirrelled them away.)

Yes.

http://www.ben.cz/_d/datasheet/tda7293v.pdf

Using SS any time at all is a sin!! Haven't you read Judas 12:17?

EWBrown wrote:
Subs are one application where using Solid State (or Soiled State) is not a "sin" as the SS circuitry really does work better at the low end of the audio spectrum, and generating relatively high power levels is not too demanding.
/ed B[/i]

BTW, the sub is for my mostly rock n roll system down in the workshop, not for the listening room.

Thanks for the tips and comments.