MOSFET sub. for ESP proj. 101

lawbadman · 4th September 2008, 10:17 PM

Hello,

I have a number of BUZ901/906 MOSFETs that have been sitting down for years doing nothing.
I have acquired a few high power transformers and heatsinks so I figure its time to build some amps

I was thinking of ESPs project 101 ( http://sound.westhost.com/project101.htm ) but the MOSFETs are very expensive. But I was wondering if I could substitute 2Sxxxxx for the BUZ901/906 that I have. I have been looking at the datasheet for both and I have noticed that the BUZs have about 33% more capacitance than the 2Sxxxxxs.
I was hoping that I could do a direct replacement but I really am not sure. Can some of you experts advise me as to whether I can make the substitution or not?

Also if you know of any other amps that I can use the BUZs in let me know.
I have the itch to build something

In any case I need a pair of amps for the woofers on my new OB speakers.

http://www.magnatec-uk.co.uk/pdf/magnatec/BUZ900DP.pdf
http://www.magnatec-uk.co.uk/pdf/magnatec/BUZ905DP.pdf

Thanks all,

Lawrence

jaycee · 5th September 2008, 01:37 AM

They should work. If in doubt, ask Rod himself

The capacitance might affect distortion a bit as the MJE350 in the circuit will have a harder job, but it shouldn't explode or anything like that.

AndrewT · 5th September 2008, 08:19 AM

as far as I have seen all the Lateral FETs are expensive cf. BJT and VFETs.

burbeck · 5th September 2008, 08:42 AM

hi there,
have you got the the 16 Amp, DP suffix devices?
these are "dual die" two fets in one can, so they will have twice the gate capacitance.

some tweaking of c11/c12 may be needed

homemodder · 5th September 2008, 09:59 AM

Nelson Pass has recently done some measurements about mosfet capacitances. I think you guys are going to be pleasantly surprised. The BUZ will perform just fine, maybe even better than the 2s.
Head over to Pass Labs and read how capacitances are affected when mosfets are used in linear operation.

4th September 2008, 10:17 PM	#1
lawbadman diyAudio Member Join Date: Mar 2003 Location: St. Catherine, Jamaica	MOSFET sub. for ESP proj. 101 Hello, I have a number of BUZ901/906 MOSFETs that have been sitting down for years doing nothing. I have acquired a few high power transformers and heatsinks so I figure its time to build some amps I was thinking of ESPs project 101 ( http://sound.westhost.com/project101.htm ) but the MOSFETs are very expensive. But I was wondering if I could substitute 2Sxxxxx for the BUZ901/906 that I have. I have been looking at the datasheet for both and I have noticed that the BUZs have about 33% more capacitance than the 2Sxxxxxs. I was hoping that I could do a direct replacement but I really am not sure. Can some of you experts advise me as to whether I can make the substitution or not? Also if you know of any other amps that I can use the BUZs in let me know. I have the itch to build something In any case I need a pair of amps for the woofers on my new OB speakers. http://www.magnatec-uk.co.uk/pdf/magnatec/BUZ900DP.pdf http://www.magnatec-uk.co.uk/pdf/magnatec/BUZ905DP.pdf Thanks all, Lawrence __________________ <a href="http://www.danasoft.com"><img src="http://www.danasoft.com/sig/lawbadman.jpg" border="0"></a><div style="font-family:arial,sans-serif;font-size:11px;"><p>Sign by Danasoft - <a href="http://www.danasoft.com">For Backgrounds and Layouts</a></p></div>

5th September 2008, 08:42 AM	#4
burbeck diyAudio Member Join Date: Aug 2004 Location: Ratae Coritanorum	hi there, have you got the the 16 Amp, DP suffix devices? these are "dual die" two fets in one can, so they will have twice the gate capacitance. some tweaking of c11/c12 may be needed __________________ regards bob

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
esp proj 19 lives! 8 channels!!!	Mattyo5	Solid State	20	7th October 2002 12:42 AM

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

5th September 2008, 01:37 AM	#2
jaycee diyAudio Member Join Date: Apr 2004 Location: Norwich, UK	They should work. If in doubt, ask Rod himself The capacitance might affect distortion a bit as the MJE350 in the circuit will have a harder job, but it shouldn't explode or anything like that.

5th September 2008, 08:19 AM	#3
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	as far as I have seen all the Lateral FETs are expensive cf. BJT and VFETs.

5th September 2008, 09:59 AM	#5
homemodder Account disabled at member's request Join Date: May 2006	Nelson Pass has recently done some measurements about mosfet capacitances. I think you guys are going to be pleasantly surprised. The BUZ will perform just fine, maybe even better than the 2s. Head over to Pass Labs and read how capacitances are affected when mosfets are used in linear operation.