If the voltage numbers you have posted are accurate, or reasonably close, you are exceeding the input voltage specs for the LM317 and LM337. I'd double check your AC voltage select switch. If it's in the 100V position and you're using 115V that would explain why the voltage out of the bridge is high.
Hi,
The schematics is part of the user manual. From what I remember, it is
the same schematics for 9300 and 9500, with two sets of values of
parts for the two amplifiers.
I have the manual but won't be able to look for it till the weekend. If you
still need it by then I'll dig it up.
Dennis
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try the link metioned earlier in the thread.
even still, i would be VERY leery buying such long discontinued JFETs.
these were hard to source even while they were still being manufactured years ago by NEC!
mlloyd1
even still, i would be VERY leery buying such long discontinued JFETs.
these were hard to source even while they were still being manufactured years ago by NEC!
mlloyd1
I would love a copy of the 9300 manual. appreciate your looking. Thank you.
Do you guys have the service manual for the 9300 ?
what is the difference between the 9303 and the 9300 ?
what is the difference between the 9303 and the 9300 ?
No , bad ESR will make the regulators prone to oscillate. Adjustable regulators are FB circuits.
According to the manual for the 9303/9505
you can use 2 2sk163/2sj74 or 1 2sk389/2sj109
what is the equivalent to the 2sj44 but dual ?
you can use 2 2sk163/2sj74 or 1 2sk389/2sj109
what is the equivalent to the 2sj44 but dual ?
Keep in mind that VDS max for those devices are dissimilar and will get you into trouble if not right away, then eventually. The NEC pair is rated 40V while the Toshiba pair is rated only 25V. For the amps, Hafler's designers set the low voltage rails at 24V, so technically speaking, you "should" be OK ... except in other threads (for example, the Blowtorch thread) we have been told by designers that when JFETs VDS exceeds certain voltages some characteristics get worse (such as noise and leakage). And, we've seen earlier in this thread that some failure modes will expose the parts to higher than 24V. As additinal background, the NEC parts are closer complements between N and P (EUVL has shown this in actual measurements), have lower capacitances in addition to higher voltage ratings and I beleive the Toshiba parts have higher transconductance and lower noise. It's also probably not the best idea to pair 2SK163 with 2SJ74 or 2SK170 with 2SJ44 unless you really know what you are doing ... (for example EUVL's trick to help improve transconductance match between the Toshiba N and P JFET pairs.
I guess I will not touch those transistors in my 9300, so leave it alone if it is working fine ?