F5X -- the EUVL Approach

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#143
Hi Patrick,

The overall dimensions are approximately 17.4" wide x 12.7" deep x 7.2" tall (roughly 442mm x 322mm x 183mm). The heatsinks themselves are 12.2" deep, 2.3" thick, and about 7" tall (310mm x 58.4mm x 177.8mm). The heatsinks have 22 fins.

Overall it is wider than your case and slightly shorter in depth.

Dave
 
#149
pmchoong,

Contact zhoufang for matched 2SK1530/2SJ201, you need 4 matched pairs NNNNPPPP (all to 10mV). Be prepared to pay around $28 a pair.

There has been a small GB from Sumr, that is now closed, at this stage you’ll have to source the transformers yourself.

Cheers
John
 
#153
no, you need 4 x matched k1530/j201 pairs, they are complementary devices. but someone correct me here if i'm off track. is it more important to match within same devices, so that the 4 x k1530 are very close and the 2 x j201 are very close and then that each quad is as close as is possible with an NN NN|PP PP pairs, because bias between the poles can be balanced with tweaking??. its best that all 8 are close, but N and P cannot truly be matched. i may be totally off base there and i'm sure someone will correct me if i am 😀
 
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#156
Each channel of F5X uses 4 MOSFETs, 2x 2Sk1530, 2x 2SJ201, all matched to each other.
So for a stereo amp, you need a set of 8 matched devices in total.

It is "expensive" as you said. But you would also be paying 300 USD for 2 transformers, something of the same amount minimum for a decent case,...... And if anything, it is worth spending money on devices which has a most direct impact on the soinic results.

So it will not be a USD600 budget amp. I am sure you can build an F5X circuit with that budget, with less selected, lower cost components. There are many threads around to tell you how to do that. But that is not what we are trying to achieve here.

As I said in Post #1, there are hundred ways to skin a cat.


Patrick
 
#157
EUVL said:
Each channel of F5X uses 4 MOSFETs, 2x 2Sk1530, 2x 2SJ201, all matched to each other.
So for a stereo amp, you need a set of 8 matched devices in total.
Click to expand...

Ok, so for our dual mono, we need 2 matched pairs for each channel ( ie. 2 x 2Sk1530 + 2 x 2SJ201).

Total = 4 matched pairs (4 x 2Sk1530 + 4 x 2SJ201, all matched)

Both channels' mosfets should matched each other, meaning the left channel's pairs should also matched the right channel's pairs.
 
#158
So it will not be a USD600 budget amp. I am sure you can build an F5X circuit with that budget, with less selected, lower cost components. There are many threads around to tell you how to do that. But that is not what we are trying to achieve here.

As I said in Post #1, there are hundred ways to skin a cat.
Click to expand...

My wife is going to skin me. Sorry for the non technical comment.
 
#159
Well, if one wants to save some bucks, different output fets are also an option as the fine Toshiba parts are next to Semisouth parts the most expensive fets.

Will it sound different? Likely so, but to the better or worse is up to personal taste.

The smallest change is to not match between N and P, as these parts are never really identical anyway.

Hannes
 
#160
Please keep this thread only for technical discussions.

After about a week's discussion with the forum (to see how our PCB could fit into the case design they are working on, separately), we have finally come to an agreement that everyone is happy with. So we can now go to the prototyping phase to make sure the PCB is error free before making it available to all.

My most sincere thanks to fitzfish for the hundreds of hours he spent on the PCB. I didn't realise how difficult it is to get all these curvy tracks with PCB software. But he did it all by hand, to my perfect satisfaction, without a word of complaint, or even letting me know it was that difficult. So it will be the first, and probably the last curvy track PCB you can get from the forum.

Finally we are progressing.


Patrick
 
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