Your amp will still work even if you do not match the transistors.
Just make sure you use the same gain grades in the complementary pairs.
Matching however will give you better distortion figures but not that much that it will ruin the sound of the amp.
I would therefore not spend 45 GPB on a transistor tester.
Balu's test set up can be done quickly and easily without spending a lot of money.
Just make sure you use the same gain grades in the complementary pairs.
Matching however will give you better distortion figures but not that much that it will ruin the sound of the amp.
I would therefore not spend 45 GPB on a transistor tester.
Balu's test set up can be done quickly and easily without spending a lot of money.
Thanks for the advice Bonsai
Just to confirm:
Therefore the above listed are the complimentary pairs that you are referring to?
Thanks again 🙂
Just to confirm:
Therefore the above listed are the complimentary pairs that you are referring to?
Thanks again 🙂
Hi Bonsai / Forum
Searching from RS (UK), for BC550C transistor [Mouser have them on backorder - factory lead time 6 weeks away], so, I have: BC550CG, BC550CBU, BC550C, BC550CTA on offer.
For BC560C: I have BC560CG or BC560CTA
Manufacturers on offer are ON Semi or Fairchild.
Not being fussy, instead, ignorant and eager to learn; how would I choose from these different parts please?
What specifications would help me choose between them?
Many thanks all 🙂
Searching from RS (UK), for BC550C transistor [Mouser have them on backorder - factory lead time 6 weeks away], so, I have: BC550CG, BC550CBU, BC550C, BC550CTA on offer.
For BC560C: I have BC560CG or BC560CTA
Manufacturers on offer are ON Semi or Fairchild.
Not being fussy, instead, ignorant and eager to learn; how would I choose from these different parts please?
What specifications would help me choose between them?
Many thanks all 🙂
BC550CTA is C gain rank on tape and reel. They also have pre-bent leads for easier insertion in the board. Same device, just easier to work with.
Fairchild is now part of ON Semiconductor.
Fairchild is now part of ON Semiconductor.
Hi guys,
Am just curious -- I like that the inductor is very easy to make, and the instructions are clear enough; but is there a commercial part (such as something from Coilcraft) that would get the inductance right on the mark at 0.6uH?
Am just curious -- I like that the inductor is very easy to make, and the instructions are clear enough; but is there a commercial part (such as something from Coilcraft) that would get the inductance right on the mark at 0.6uH?
Hi guys, another quick question -- on the sx amp power supply, I notice that if I mount the rectifier at the bottom of the PCB as shown on p. 32, the positive leg of the rectifier goes into the negative leg, so the polarity of the whole supply goes the other way. Shouldn't the notched end face away from the edge of the PCB?
If I were to use a free-standing heatsink instead, would a 2.5" one work instead? Thanks in advance.
If I were to use a free-standing heatsink instead, would a 2.5" one work instead? Thanks in advance.
Hi guys,
If the C6 & C9 capacitor recommended is unavailable are the Panasonic 22000uf 50v audio grade capacitors on eBay likely to be genuine and the right thing to use as a replacement?
Any help much appreciated,
Josh
If the C6 & C9 capacitor recommended is unavailable are the Panasonic 22000uf 50v audio grade capacitors on eBay likely to be genuine and the right thing to use as a replacement?
Any help much appreciated,
Josh
Why insert the rectifier from the wrong side of the PCB?
Surely it only makes sense to mount the rectifier on the correct side where as you have noticed , the lead outs line up with the correct pads !
Ebay retailers are very variable. From crooks to first class.
You need to assure yourself that the retailer you have chosen is honest and reliable and that their guarantee holds good if you need to complain that they have inadvertently supplied fake components.
Be careful and check what you receive.
One Member here almost went bankrupt when he organised a group buy that turned out to be very popular.
He bought thousands of faked jFETs and distributed them around the world without doing any component testing.
He had to recover all these fake devices because the seller would only reimburse on the basis of returned product. It seems the seller would not pay the return postage. Insist that your Retailer does pay return postage if they supply faulty or fake goods.
One Member here almost went bankrupt when he organised a group buy that turned out to be very popular.
He bought thousands of faked jFETs and distributed them around the world without doing any component testing.
He had to recover all these fake devices because the seller would only reimburse on the basis of returned product. It seems the seller would not pay the return postage. Insist that your Retailer does pay return postage if they supply faulty or fake goods.
I would stick to buying your capacitors from a reputable distributor - these are critical parts - don't take chances.
Re the rectifier - you have bent the leads the wrong way . . .
Some builders mounted the rectifiers on the top side of the PCB, but added a heatsink.
Re the rectifier - you have bent the leads the wrong way . . .
Some builders mounted the rectifiers on the top side of the PCB, but added a heatsink.
Hi guys,
two questions:
1- is there a problem if i used the Front end stages transistors (Q8-Q9-Q10-Q11) all BC546B /BC556B... i know they differ in Vceo but is it critical .
2- is there a problem if i omitted the SC protection(U1- R7- R2-J1) and used another power supply ( just for testing with a bench power supply and till ican get the FODM Opto?
two questions:
1- is there a problem if i used the Front end stages transistors (Q8-Q9-Q10-Q11) all BC546B /BC556B... i know they differ in Vceo but is it critical .
2- is there a problem if i omitted the SC protection(U1- R7- R2-J1) and used another power supply ( just for testing with a bench power supply and till ican get the FODM Opto?
Thanks Andrew ... you just made my day because i only have those 546b and 556b and can't wait to complete the amp.
I think it is time someone redraw the sx pcb for smd input transistors.😉
Bc8xxc are common parts available everywhere.