small amp for percission - help

Wobbie · 14th December 2010, 08:24 AM

Hey all, need a little help.

Trying to build a small amp (see attachment)

Basically i want to build a box i stomp on, with a piezo transducer in it

i want out the big bass thump sound similar to a bass drum

output from the (small) amp will be to my gig setup amp.

Any help would be madly appreciated...

i have built this circuit on the breadboard it works well with a small speaker but when i plug it into my peavy 100w amp i get really bad humm.

once again any help will be madly appreciated.

Thanks

Wobbie · 15th December 2010, 05:06 AM

Should say percussion !! My bad

Spiny · 09:53 PM

Ground loop maybe How are you powering the stomp box? from a wall-wart?
Try on battery power first, if its quiet then look to the power unit. This can a problem when connected to the Peavy as thats grounded as well as the power supply. In this case running on the internal speaker it will not hum.

For a mains power supply try a regulator (7809?) and some caps to tame the hum. Good luck

firechief · 15th December 2010, 09:56 PM

PIE20 is that the pizo device? Have you got one? Where can we see data on it? Do you want to be able to change the tone? or just the same all of the time?

N-Brock · 15th December 2010, 09:59 PM

Pretty sure it says "PIEZO" not "PIE20".

Andrew Eckhardt · 15th December 2010, 10:19 PM

Are you trying to generate an LF pulse, like a bass drum, with the piezo element?

firechief · 15th December 2010, 10:51 PM

Quote:

Originally Posted by N-Brock

Pretty sure it says "PIEZO" not "PIE20".

By george I think your right!

Wobbie · 17th December 2010, 08:57 AM

Lol, Sorry for my poor writing skillz, it does say Piezo..

Andrew, Yes i am trying to generate a sound similar to a bass drum from the box.
the piezo and the "little amp" will be mounted in the box, output via 6.5mm mono to my 110 watt amp.

Firechief. Yes i have 3, 45mm piezo discs $5 from eBay. Not sure on the specs. perhaps would be advantageous to change the sound, maybe even get some sort of resonance / reverb if this is possible (and not above the skill level of a beginner diy). suggestions?

Spiny. I have been powering it from a 9v pp3 battery, all ground lines shown on the schematic are linked to the - terminal of the battery ( i think this is my problem as there is no "actual earth" basically i get an ok sound, but i get some "MAD" humm even at low volume levels.

out of interest i have also been trying to duplicate a similar device from a TL072 opamp with no success.

15th December 2010, 05:06 AM	#2
Wobbie diyAudio Member Join Date: Dec 2010 Location: Tassie	Whoops. Should say percussion !! My bad

15th December 2010, 09:48 PM	#3
Spiny diyAudio Member Join Date: Feb 2008	Ground loop maybe How are you powering the stomp box? from a wall-wart? Try on battery power first, if its quiet then look to the power unit. This can a problem when connected to the Peavy as thats grounded as well as the power supply. In this case running on the internal speaker it will not hum. For a mains power supply try a regulator (7809?) and some caps to tame the hum. Good luck Last edited by Spiny; 15th December 2010 at 09:53 PM.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
small-signal (small-power) fast switching complementary transistors	Lola Luna	Solid State	3	8th April 2010 07:51 PM
Small speakers for a small tube amp	jeppix	Full Range	17	29th January 2010 08:10 AM
Small-signal (or small power) pentode that can handle 400V (or more)?	GordonW	Tubes / Valves	12	13th June 2008 02:07 AM
Will this work? Disassamble my old three ways & make small speakers w/seperate woofer	chris conery	Multi-Way	0	18th April 2007 10:46 PM
PC-speakers + small amp (key words: small, cheap)	rho	Multi-Way	8	18th May 2006 01:19 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

15th December 2010, 09:56 PM	#4
firechief diyAudio Member Join Date: Sep 2008 Location: Near Seattle Wa	PIE20 is that the pizo device? Have you got one? Where can we see data on it? Do you want to be able to change the tone? or just the same all of the time?

15th December 2010, 09:59 PM	#5
N-Brock diyAudio Member Join Date: Oct 2007 Location: Cambridge, MA	Pretty sure it says "PIEZO" not "PIE20".

15th December 2010, 10:19 PM	#6
Andrew Eckhardt diyAudio Member Join Date: Nov 2005 Location: PA	Are you trying to generate an LF pulse, like a bass drum, with the piezo element?

17th December 2010, 08:57 AM	#8
Wobbie diyAudio Member Join Date: Dec 2010 Location: Tassie	Lol, Sorry for my poor writing skillz, it does say Piezo.. Andrew, Yes i am trying to generate a sound similar to a bass drum from the box. the piezo and the "little amp" will be mounted in the box, output via 6.5mm mono to my 110 watt amp. Firechief. Yes i have 3, 45mm piezo discs $5 from eBay. Not sure on the specs. perhaps would be advantageous to change the sound, maybe even get some sort of resonance / reverb if this is possible (and not above the skill level of a beginner diy). suggestions? Spiny. I have been powering it from a 9v pp3 battery, all ground lines shown on the schematic are linked to the - terminal of the battery ( i think this is my problem as there is no "actual earth" basically i get an ok sound, but i get some "MAD" humm even at low volume levels. out of interest i have also been trying to duplicate a similar device from a TL072 opamp with no success.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)