This is a bom of the most currently revised transistor matcher, hence, it will require modification based on the older version that I sold. For example, the dip switch required is a 6 position NOT the 8 position listed in this BOM, also you won't need to purchase all the resistors listed because of the 8 position dip listed in this BOM. So just subtract 2 of the listed resistors that are specific to the dip switch. Remember you can exclude the caps parallel to the precision resisters. The schematic attached is correct for the matcher board I've been selling
Should be on page 23. Used during testing without output transistors installed.
J103 is only installed when testing up to driver when the outputs are not installed. It is removed once the outputs are installed.
Jeremy
Jeremy
If anyone in the US is having trouble sourcing or making the inductor, I’m willing to make extra epoxy dipped coils for $10 shipped per pair. Pm if interested, I probably have enough wire for a dozen coils.
An LCR bridge is able to measure a coil.
Best regards
rephil
Best regards
rephil
LCR meter. If you follow the build guide on wire size and dimensions, you shouldn't need to measure them, they will be close enough. There are also calculators online for air core inductors, which calculate inductance by size/turns.
Hi DaveFred
A good LCR Meter is the DER EE DE-5000, not very expensive, but a good meter. It can be expanded for measuring small parts too. You will find it in eBay, Amazon ...
Best regards
rephil
A good LCR Meter is the DER EE DE-5000, not very expensive, but a good meter. It can be expanded for measuring small parts too. You will find it in eBay, Amazon ...
Best regards
rephil
Just measured my output transistors out of curiosity, all the NPN transistors are around 108hfe and my PNP are around 70hfe. I am using 2SA1943N and 2SC5200N. Is this OK or should I just order another batch of both and hope I can get them closer in hfe?
edit - just checked post 150 maybe this is ok ?
edit - just checked post 150 maybe this is ok ?
What is the rated output of these? I am converting my speakers to active and looking for tweeter amps.I am looking for 3 channels
What is the minimum standoff height if mounting the board parallel to the heatsink? I was planning on 10mm, but it might be good to check. I am running 71V rails.
Build Guide recommends min 8mm and max 10mm.
Personally, I think 10mm leaves too little lead length on the EF3-4 boards for safe soldering the Vbe TO126 transistors, especially if their leads are bent conservatively a little further from the transistor body.
If anyone's wondering what the updated matcher looks like, here it is.
Attachments
I found 10mm fine, but you need to take care with bending the leads as it is on the limit as Johno suggested.
Hope this helps
- Dan
I have the DER EE LCR Meter DE-5000, I highly recommend this one
