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QRV01 output stage

Started by goldkenn, July 31, 2010, 08:03:32 PM

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goldkenn

Not sure I should use both T19/20/21/22 along with T24/25/26/27 or either one set?

peranders

I can help you next weekend with this.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn

If possible, please advise a working configuration, since from QSXM2 phono, due to too many opttions, I wasted too much time and money upon SMD configuration (finally not working using SMD transisitors, I know more calculations and testing upon something like resistor value could make it work but I did spent too much on it, so finally simply swapping back to all BC550C/560C configuration), and as QRV01 have almost the same many options as QSXM2, I am tried for possible configurations, thanks peranders :-)

peranders

The reason for having footprints for SOT23 was that it's easier to find good parts and harder in TO92. They have the same performance if they have the same data.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn

#4
Bt the way, other then the output stage:
1) Can I use SSM-2210/SSM-2220 for MT1/2/3/4? If okay then what resistor value should I use for current supply?

2)  The "class A temperature regulation circuit " you mnetioned to forget is which part? Am I need to omit some parts or do some jumper wiring for modifications?

3) Any easy find replacement (possible to buy from RS or Farnell) of BF471/BF472? Nothing could find here in Hong Kong, and I am not sure which replcement no need for any re-calculation of components value.

Thanks!

goldkenn


peranders

1 You don't have to change anything.

2 Omit R47, OC1, IC10 and all parts around. The same goes for the other channel in corresponding locations.

3 Use BC5xx transisitors if you can't find any similar types with low capacitances.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

peranders

Quote from: goldkenn on July 31, 2010, 08:03:32 PM
Not sure I should use both T19/20/21/22 along with T24/25/26/27 or either one set?

T19-T22 or T24-T25 or T26-T27
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn


peranders

The suggested type will almost fit but not entirely.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn

Which from farnell could entirely fit? Since some pdf not in English, I can't make sure the measurement.

peranders

/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn

Did MJE345/350 replace BF471/472 perfect in QRV01? I found serveral pairs MJE340/350 from my drawer, and I serach did found many examples they do replace each others and work great, however, the pdf of MJE340/350 have not shown the capacitance, since you have mentioned low capacitance is needed, will MJE340/350 work?

peranders

MJE340 is a small power transistor with for me unknown HF properties. I would use the BC transistors in this position.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

goldkenn

How to tune P1 and P3? Can't find any info since you have not yet finishe the instrcution section yet......