6L6: Got the kit yesterday and thanks for your excellent packaging -- very professional. Would like to get the 2SK370 through-hole Jfet substitutes and cannot find them on Mouser or DigiKey. Where are they available? Will the Jfets available on DIY work as well? If so, which ones? Am most interested in avoiding the SMD soldering -- having struggled through them on 4 of Wayne's fine preamp pcbs (and thanks, Wayne!). Apreciate your response.
Hello,
I used 2SK209 already soldered to ting adaptor PCB's. They worked out real well. take a look at the link in the post below.
https://www.diyaudio.com/community/threads/pearl-3-burning-amp-2023.404054/page-82#post-7559000
Thanks DT
2SK370 have been out of production for well more than a decade. I’m not sure what you ordered, if it was the 2SK3700(f) …
https://www.digikey.com/en/products/detail/toshiba-semiconductor-and-storage/2SK3700-F/2062697
…that’s about as wrong a N channel mosfet as you could possible use in that position.
If you absolutley have to have through-hole devices, order an octet of 2SK170 from punkydawgs on ebay with as low an Idss as he has, or perhaps just consider using the 2SK209 that are included in the kit, because they work perfectly, as the circuit was designed around them.
https://www.digikey.com/en/products/detail/toshiba-semiconductor-and-storage/2SK3700-F/2062697
…that’s about as wrong a N channel mosfet as you could possible use in that position.
If you absolutley have to have through-hole devices, order an octet of 2SK170 from punkydawgs on ebay with as low an Idss as he has, or perhaps just consider using the 2SK209 that are included in the kit, because they work perfectly, as the circuit was designed around them.
6L6: Suspected this was the issue with the original 2SK370 series and have cancelled the DigiKey items. Because of a large number of EBay problems, no longer order parts from this source. Will consider DT's suggested items when they arrive. SMDs cause me great problems in assembly and would spend a significant amount on through-hole substitutes -- as long as they do not degrade performance and come from a reputable company.
Dennis: Can do smd soldering and have built 4 of the preamp boards that require this. It is, however, so unpleasant that I pursue any alternatives. Move back and forth between summer and winter places but do most builds in my Flagstaff AZ home. Any of the DIYers are invited to visit me there -- but only after May 15th.
@Craigl59 In 1 of the threads I posted a tip for soldering SMDs and some others posted other suggestions. Can't find the posts now, but a fellow on YouTube lightly tins 1 pad, flux is an essential soldering aid, then hold the SMD in place with a tweezer and heat the solder till it bonds, then solder the other leg and retouch the first 1.
Toys4Boys: Have seen the videos above and they are very good. Have also been using this technique for several years and just find it SO unpleasant to solder smds that I will try any alternative. Have got the thin solder, tiny tips, and plenty of liquid flux paste. Doesn't get any easier...
@Craigl59
If you´re still interrested in TO-92, I could try to match 2 quartets of Toshiba´s 2SK170.
Could be GR´s of the highest IDSS or BL´s of the lowest. It might take me a couple of days though, so
will only go ahead with this, if you´re absolutely sure, you can´t live without them
If you´re still interrested in TO-92, I could try to match 2 quartets of Toshiba´s 2SK170.
Could be GR´s of the highest IDSS or BL´s of the lowest. It might take me a couple of days though, so
will only go ahead with this, if you´re absolutely sure, you can´t live without them
These are genuine NOS Toshiba´s. Seems the store only carries the Linear Syatem ones.
GR´s IDSS range is from 2-6mA, BL´s are 6-12mA..
Don´t know about your last Q, but ordering from the US will probably save you some customs hazzle.
Probably depends on the value written on the customs label.
Send me a PM if you want these. I certainly would hate to pour them out on my workbench and start the matching,
if I´m not sure you want them after I´ve gone through the trouble
PayPal is fine (family and friends or you pay the fee).
GR´s IDSS range is from 2-6mA, BL´s are 6-12mA..
Don´t know about your last Q, but ordering from the US will probably save you some customs hazzle.
Probably depends on the value written on the customs label.
Send me a PM if you want these. I certainly would hate to pour them out on my workbench and start the matching,
if I´m not sure you want them after I´ve gone through the trouble
PayPal is fine (family and friends or you pay the fee).
Hello All,
In my measurements I found that installed in the P3 2sk170 fets run at very near 40% of IDSS.
So for 8 each matched at 7ma IDSS 2SK170's they will run at 2.8 ma each in the P3 PCB.
I ended up using the 2SK209 soldered on the tiny PCB's then soldered in the through hole locations on the P3 PCB's
Thanks DT
In my measurements I found that installed in the P3 2sk170 fets run at very near 40% of IDSS.
So for 8 each matched at 7ma IDSS 2SK170's they will run at 2.8 ma each in the P3 PCB.
I ended up using the 2SK209 soldered on the tiny PCB's then soldered in the through hole locations on the P3 PCB's
Thanks DT
Another Pearl III is up and running - First Test run - all stock.
Worked pretty much without issues, apart from some reversed LEDs.
Mistook the "+" for C20 to be for D3, but it worked once that was fixed.
Now starts the opamp rolling. Looking to try the New Burson V7s. Would love some free samples.
Need to get the XLR outlets in.
Worked pretty much without issues, apart from some reversed LEDs.
Mistook the "+" for C20 to be for D3, but it worked once that was fixed.
Now starts the opamp rolling. Looking to try the New Burson V7s. Would love some free samples.
Need to get the XLR outlets in.
My Pearl 3 sounds great, however it's susceptible to static electricity via the turntable and spikes in the AC power network. When I switch on the power of my CD player, I hear a thump through my speakers when phono is selected on the preamp (not when I select another source). Could this be linked to the ground/earth of the Pearl 3? Wiring is according to build guide.
Hello,
Try using only 3 of those 2SK170's rather than 4 per PCB. The total current will be reduced by 25% to right at 9 ma per P-3 PCB.
Thanks DT