2N3707 Substitutes?

[soundguy]

did a search, didnt come up with much. Can anyone reccomend a substitute for the 2N3707 used in an 1176? Will a 2N5088 work? For some reason the 1176 Im working on has 2n5088's stuffed in place and I think that might be part of my problem today...

dave

 

[soundguy]

actually, comparing the central datasheets, the 5088 shouldnt be a problem, right? I linked through the data sheets at mouser. Any good reason not to use a 5088 in place of a 3707? Any other suggestions?

dave

 

[edanderson]

i've seen them substituted in 1176s with no problem. also, i have some 2n3707s if you really want them. but 2n5088s should work fine.

ed

 

[Gus]

just looked at a data sheet for the 2n3707 the pinout is ecb

the 5088 should be ebc

I would check the pinout. I would need to look at the schematic and where the 5088 are being used for more ideas.

 

[soundguy]

yes, noticed the difference between the pinout. I compared to a 3391a which has the same pinout as a 3707 and was able to find a bunch that I had with hfe over 400, so I used those throughout the whole 1176 in place of 3707. I got the line amp working but cant get it to compress, Im gonna update my other thread...

dave

 

[edanderson]

if the sidechain amp isn't working with 2n3391as, you should swap them all for 2n5088s. also, Q5 the second transistor in the line amp should probably be changed out for a 2n5088.

ed

 

[soundguy]

Im gonna try that now, the meter driver amp is working fine, but I dont really hear any compression and there is no change in distortion when adjusting the attack and release controls.

dave

 

[adrianh]

Warning thread hijack!

Dave how are you measuring Beta (Hfe)?

 

[soundguy]

my multimeter has a transistor socket on it. Is that not an accurate method to determine hfe? Im figuring that if it isnt a good measure of the true beta, its probably good enough to sort transistors into similar batches, right?

dave

 

[PRR]

> I dont really hear any compression

Are you feeding it enough signal?

Enough UN compressed very dynamic signal?

This is an FET limiter, right? Put a voltmeter on the FET gate. A high-impedance (VTVM) needle-meter is much better than a DVM, but a DVM will be much better than a basic passive needle multimeter.

 

[soundguy]

PRR, on ed's suggestion I swapped out the 2n3391a's in the sidechain for 2n5088's, calibrated it and it completely rocks.

It is a fet limiter.

A VTVM on the gate should show a drop or increase in voltage when the fet goes into compression? Just curious.

thanks

dave

 

[Spencerleehorton]

could a BC550 work?

 

[midwayfair]

could a BC550 work?

Reverse pinout. If you need <500hFE, use the C suffix and you're more likely to hit the target. A 549A or B won't be in that gain bucket very often.

 

[Spencerleehorton]

ah ok, so a BC550C should work fine right?