The vendor asked for what IDSS I need. When specifying "BL" does it automatically answer his question? or do I need to be more specific?
2SK170BL/2SJ74BL. BL: 6-12 mA (really 6.8-11 mA). This is the spec I got from him.
Much appreciate any help. Thanks.
~Kecap
I got mine from here: Toshiba 2SJ74 + 2SK170 LAB MATCHED QUAD to 0.03mA AND 4mV (7-8ma range) | eBay
This discussion has made me realize that they're different from the ones in the diyaudio store (now sold out). Unfortunately that means I've got B versions in one monoblock and As in the other. Didn't realize there were different types. Dammit.
This discussion has made me realize that they're different from the ones in the diyaudio store (now sold out). Unfortunately that means I've got B versions in one monoblock and As in the other. Didn't realize there were different types. Dammit.
Genuine Toshiba 2SK170BL/2SJ74BL high transconductance JFET complimentary pair | eBay
Whoops
And note that they state: "Important notice: as of 6/10/2019, there are ZERO parts between 8.0 mA and 9.5 mA left. They have all been sold. Will we get more? Not until the parts we still have on hand are sold. It is my understanding when we reach the end of the parts we have on hand that we will then receive more parts. (At least that is the plan.)"
Whoops
And note that they state: "Important notice: as of 6/10/2019, there are ZERO parts between 8.0 mA and 9.5 mA left. They have all been sold. Will we get more? Not until the parts we still have on hand are sold. It is my understanding when we reach the end of the parts we have on hand that we will then receive more parts. (At least that is the plan.)"
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~~~~~
A quick note that somehow the text of my link is to a punkydawgs listing, but the link itself goes to the A types I bought from another source.
Here's the PD link: Toshiba 2SJ74 + 2SK170 LAB MATCHED QUAD to 0.03mA AND 4mV (7-8ma range) | eBay
Anyone knows or measured the heat dissipated by the rectifiers ?
Do they really need sinking to case like Zen nicely did in his "papas koan" superb build?
I ask because i can solder them directly on the rectifier circuit board, but in this case they will "float"
BUT
if they heat up under the full load i can do extensions and mount them on the underlying steel case.
But i cant see much benefit on mounting them on steel or even painted steel.
Anyway I guess my question narrows down to : how much will a rectifier dissipate under 10 A load if it is rated @50A and drops 1.1V?
Sinking it onto the painted steel bottom case even enough (considering i have 2 of them)? I must be missing something. (happened before 🙂)
Do they really need sinking to case like Zen nicely did in his "papas koan" superb build?
I ask because i can solder them directly on the rectifier circuit board, but in this case they will "float"
BUT
if they heat up under the full load i can do extensions and mount them on the underlying steel case.
But i cant see much benefit on mounting them on steel or even painted steel.
Anyway I guess my question narrows down to : how much will a rectifier dissipate under 10 A load if it is rated @50A and drops 1.1V?
Sinking it onto the painted steel bottom case even enough (considering i have 2 of them)? I must be missing something. (happened before 🙂)
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I had Dodo ones , because builder of FW sort of amp did not put split washer , so bridge became loose
go figure , do they need heatsinking or not
go figure , do they need heatsinking or not
they drop 1.1V so ... no
but why:
P=VI so dissipates 1.1*10 ~11w
so no... i'm an idiot after 12AM
Hi escucalin,
that package can't dissipate ~10W without heatsinking.
At least not without overheating and going Dodo, to speak in Zen Mod's words 😀
Regards,
Claas
that package can't dissipate ~10W without heatsinking.
At least not without overheating and going Dodo, to speak in Zen Mod's words 😀
Regards,
Claas
Recently I have been using active bridges in my Class A PSU’s. They use low RDSon MOSFETs to switch and have essentially zero heat generation plus they are quieter. Also essentially no voltage drop for more headroom. Really like how they work. More info in SLB thread.
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count on , say, 1V3 of voltage drop .... or something like that
dissipation is indeed VI , in case of dual mono PSU you'll have one Iq for I , but in case of shared PSU between channels , that's 2x Iq
so , for latter - 1V3x (say) 2x 1A6=4.16W
and I know for sure that they tend to go Dodo , in shared PSU , inside of an A class amp case , when dangling on the base plate
I've been running F4's parallel since last summer ended. With the return of unpleasant heat and air conditioning I'm considering removing the power and signal to one side in each - unsoldering or unscrewing wires from terminals on the PSU and remove a signal cable.
Speakers are probably 4 ohm - but there isn't consistent information on them, I've seen papers posted with "4 ohm nominal" as well as "4 to 8 ohm".
I wish I had a way of making measurements before and after but have been lazy about purchasing a microphone or other test tools.
First, am I missing anything obvious to the oblivious? Perhaps more power on "thump"? I'm using DIYAudio store PSU's with 60,000 uf per rail.
Expected results?
Speakers are probably 4 ohm - but there isn't consistent information on them, I've seen papers posted with "4 ohm nominal" as well as "4 to 8 ohm".
I wish I had a way of making measurements before and after but have been lazy about purchasing a microphone or other test tools.
First, am I missing anything obvious to the oblivious? Perhaps more power on "thump"? I'm using DIYAudio store PSU's with 60,000 uf per rail.
Expected results?
nothing wrong can happen if you do what you wrote ; you'll have half power on 4R , but most likely you'll find it enough
of course , if you find partying so amusing , you'll stop bothering with heat issue , and bring them back to full blast
of course , if you find partying so amusing , you'll stop bothering with heat issue , and bring them back to full blast