matched pair?
Hi,
where can I get a matched pair Q1 & Q2's?
I'm filling out my order @ digikey and can't find the 2sk370 or 2sj108 (let alone get them matched.)
I've found all the other parts on digikey no problem ( a bit more than I thought I would spend on parts for one channel.)
Any suggestions?
Hi,
where can I get a matched pair Q1 & Q2's?
I'm filling out my order @ digikey and can't find the 2sk370 or 2sj108 (let alone get them matched.)
I've found all the other parts on digikey no problem ( a bit more than I thought I would spend on parts for one channel.)
Any suggestions?
Re: matched pair?
www.tech-diy.com - very good outlet for little parts.
I still dont understand on F5, if we are matching q1 to q1 (other channel) or q1 to q2 on same channel. I assume the later.
merlin2069er said:
www.tech-diy.com - very good outlet for little parts.
I still dont understand on F5, if we are matching q1 to q1 (other channel) or q1 to q2 on same channel. I assume the later.
(I'm in Canada, and they won't ship to an unconfirmed paypal address.)Re: Re: matched pair?
As others have noted, it's not really practical to match N- and P-channel devices. (ie. impractical to match q1 to q2) Also, since we don't match q1 to q2 or q3 to q4, there wouldn't seem to be much point to match left and right channel q1s. One completely unmatched set should be as good as any other completely unmatched set.
-j
Tea-Bag said:
As others have noted, it's not really practical to match N- and P-channel devices. (ie. impractical to match q1 to q2) Also, since we don't match q1 to q2 or q3 to q4, there wouldn't seem to be much point to match left and right channel q1s. One completely unmatched set should be as good as any other completely unmatched set.
-j
I agree. Tech-Diy had my stuff to me in less than a week. About as fast as Mouser or Digikey via usps and it was well packed.
Here is a ? for Nelson or others:
Nelson,
One of the most peculiar and interesting things about the F5 to me is that it is void of capacitors in the signal path. Have you considered (perhaps for a different Fx amplifier) creating a similar amplifier that is SETransistor in nature (capacitorless)? Almost like a DC SET tube amp (without the OPT and the tubes of course)?
Chris
try to get Idss of Q1 & Q2 to match within a few percent.
Both pass the same current and matching Idss gets both devices onto similar parts/slopes of the transconductance curve.
I think it will difficult to set up a matching jig to try to match the transconductance as well as the Idss of Nchannel to Pchannel.
It's relatively easy, but very labour intensive to match Idss AND transconductance over a small range of Id with all Nchannel OR all Pchannel.
The yield from this supermatching is very low with small batches (say 25 off) and still not great with 100 off batches.
Both pass the same current and matching Idss gets both devices onto similar parts/slopes of the transconductance curve.
I think it will difficult to set up a matching jig to try to match the transconductance as well as the Idss of Nchannel to Pchannel.
It's relatively easy, but very labour intensive to match Idss AND transconductance over a small range of Id with all Nchannel OR all Pchannel.
The yield from this supermatching is very low with small batches (say 25 off) and still not great with 100 off batches.
Re: Re Paypal
After Nelson mentioned the webstore I got a flood of orders, and a number of flakes...and attendant chargebacks. It's just wonderful as a vendor to see someone who filed a chargeback proclaim how wonderful their F4 or F5 sounds.
PayPal is awful for vendors. Even with USPS proof of delivery you can get hit with a charge-back. I am thinking of shutting the webstore down, or just selling PCB's for the National Semi Overture series.
Lesp said:
After Nelson mentioned the webstore I got a flood of orders, and a number of flakes...and attendant chargebacks. It's just wonderful as a vendor to see someone who filed a chargeback proclaim how wonderful their F4 or F5 sounds.
PayPal is awful for vendors. Even with USPS proof of delivery you can get hit with a charge-back. I am thinking of shutting the webstore down, or just selling PCB's for the National Semi Overture series.