Pass DIY Addict
Joined 2000
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Received my kit the other day. Many thanks to everyone who had a hand in organizing this! I am looking forward to another build. My wife is already giving me that funny look (again)...
On a related note, I managed to pick up some additional Vfets before they disappeared and finally got around to measuring them last night. The J28s measured 7.5, 7.6, 8.2, 8.2, 8.2, 8.6, and then 11.5 and 12.3. The last two seemed to behave quite a bit differently than the previous ones when I measured them, though. When powered up, the lower voltage ones displayed a voltage reading across the 1R0 resistor of about 0.1 to 0.15 volts, which dropped down to zero quickly, and then rose as I turned the pot. The two higher ones began with a reading across the 1R of about 0.3v and took very little adjustment of the pot to reach the target 0.5v reading in order to measure Vgs. Is this normal behavior for these two Vfets?
On a related note, I managed to pick up some additional Vfets before they disappeared and finally got around to measuring them last night. The J28s measured 7.5, 7.6, 8.2, 8.2, 8.2, 8.6, and then 11.5 and 12.3. The last two seemed to behave quite a bit differently than the previous ones when I measured them, though. When powered up, the lower voltage ones displayed a voltage reading across the 1R0 resistor of about 0.1 to 0.15 volts, which dropped down to zero quickly, and then rose as I turned the pot. The two higher ones began with a reading across the 1R of about 0.3v and took very little adjustment of the pot to reach the target 0.5v reading in order to measure Vgs. Is this normal behavior for these two Vfets?
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Mines still stuck in customs, I hope they havnt decided to keep it for themselves, its been there a week.
Russel, here in Cologne it sometimes takes a month. So there is still hope [emoji2]
Hi,
I have just receive the kit, I am impatient to compare it to l'Amp (the coil version).
I have make a draft BOM.
I can't find Q13 and Q14 references.
I sent the draft BOM, if it can help, and if you want to make comments.
Thank all !
TYPE
NB
0,1 1 0,25W ? Vishay Dale 10 2 0,25W ? Vishay Dale 47,5 3 0,25W ? Vishay Dale 150 1 0,25W ? Vishay Dale 221 6 0,25W ? Vishay Dale 332 1 0,25W ? Vishay Dale 750 1 3W Panasonic ERX-FJR ? 10k 2 0,25W ? Vishay Dale 15K 2 0,25W ? Vishay Dale 1K 4 0,25W ? Vishay Dale 2,2K 1 0,25W ? Vishay Dale 22k 1 0,25W ? Vishay Dale 3,32k 6 0,25W ? Vishay Dale 39k 2 0,25W ? Vishay Dale 4,75k 9 0,25W ? Vishay Dale 47,5K 1 0,25W ? Vishay Dale 47K 2 0,25W ? Vishay Dale 7,5k 2 0,25W ? Vishay Dale 47 P1-2 2 5K BOURNS 3386K ???? P3-4 2 500 BOURNS 3386K ???? Q1 1 IRF240 N MOSFET VISHAY IRFP240PBF Q2 1 IRF9240 Q3-6 4 SIT Q 7-10 17-18 6 TL431 Q11 1 2sk170 or lsk linear system Q12 1 2sj74 or lsj linear system Q13 1 ? Q14 1 ? Q15 1 2SJ313 Q16 1 2SK2013 Q17-18 2 TL431 D1-2 2 1N4004 Z1-2 5-6 4 9V VISHAY BZX85B9V1-TR ? Z4-5 2 15V LED 28V? CREE C566C-BFN-CS0W0352 ? C1-8 11-12 10 220 µF ? ELNA RFS-50V221MJ6#5 4 Heasinks
I have just receive the kit, I am impatient to compare it to l'Amp (the coil version).
I have make a draft BOM.
I can't find Q13 and Q14 references.
I sent the draft BOM, if it can help, and if you want to make comments.
Thank all !
TYPE
NB
0,1 1 0,25W ? Vishay Dale 10 2 0,25W ? Vishay Dale 47,5 3 0,25W ? Vishay Dale 150 1 0,25W ? Vishay Dale 221 6 0,25W ? Vishay Dale 332 1 0,25W ? Vishay Dale 750 1 3W Panasonic ERX-FJR ? 10k 2 0,25W ? Vishay Dale 15K 2 0,25W ? Vishay Dale 1K 4 0,25W ? Vishay Dale 2,2K 1 0,25W ? Vishay Dale 22k 1 0,25W ? Vishay Dale 3,32k 6 0,25W ? Vishay Dale 39k 2 0,25W ? Vishay Dale 4,75k 9 0,25W ? Vishay Dale 47,5K 1 0,25W ? Vishay Dale 47K 2 0,25W ? Vishay Dale 7,5k 2 0,25W ? Vishay Dale 47 P1-2 2 5K BOURNS 3386K ???? P3-4 2 500 BOURNS 3386K ???? Q1 1 IRF240 N MOSFET VISHAY IRFP240PBF Q2 1 IRF9240 Q3-6 4 SIT Q 7-10 17-18 6 TL431 Q11 1 2sk170 or lsk linear system Q12 1 2sj74 or lsj linear system Q13 1 ? Q14 1 ? Q15 1 2SJ313 Q16 1 2SK2013 Q17-18 2 TL431 D1-2 2 1N4004 Z1-2 5-6 4 9V VISHAY BZX85B9V1-TR ? Z4-5 2 15V LED 28V? CREE C566C-BFN-CS0W0352 ? C1-8 11-12 10 220 µF ? ELNA RFS-50V221MJ6#5 4 Heasinks
)
I still think all of Papa's generosity is just one more step on his path toward liberation from Samsara.
So attached is what I propose for the VFET SuppleMental Parts Kit. It might be easier to print out and tape together , as the second page is just a continuation of the lines on the first page..
It looks like it will cost about $85 by the time we order from Digi-key. We will of course get a price break, but by the time we receive the parts, pay shipping and taxes, pack in little bags and ship them to our Order Fullfillment people, there's not a huge savings. Or you can look at it as you don't have to spend the tedious time ordering, and you get all you need, with no effort and pay no more..
At the moment the package doesn't include the matched JFETS as you can order them from the store at the same time as the kit (if we do the kit.) I think I could get the kit packed up in about 6 weeks.
Matching enough JFETS for everyone will add about a month to the time frame, which is why I'm keeping them separate for now. Nelson, says that since this is a complementary amp, NOTHING needs to be matched., including the JFETS, but usually we match the JFETS because everyone feels better about it. If people don't care about matching them I can probably include JFETS in the 6 week time frame. If you want the matched JFETS, there aren't enough matched sets in the Store, so it will take about 10 weeks total if you want that.
At the least this will help you order. I need some of you to review my spec to see if there are mistakes or better options. I'm very open to suggestions.. I'm becoming spiritual like Nelson
Mark
It looks like it will cost about $85 by the time we order from Digi-key. We will of course get a price break, but by the time we receive the parts, pay shipping and taxes, pack in little bags and ship them to our Order Fullfillment people, there's not a huge savings. Or you can look at it as you don't have to spend the tedious time ordering, and you get all you need, with no effort and pay no more..
At the moment the package doesn't include the matched JFETS as you can order them from the store at the same time as the kit (if we do the kit.) I think I could get the kit packed up in about 6 weeks.
Matching enough JFETS for everyone will add about a month to the time frame, which is why I'm keeping them separate for now. Nelson, says that since this is a complementary amp, NOTHING needs to be matched., including the JFETS, but usually we match the JFETS because everyone feels better about it. If people don't care about matching them I can probably include JFETS in the 6 week time frame. If you want the matched JFETS, there aren't enough matched sets in the Store, so it will take about 10 weeks total if you want that.
At the least this will help you order. I need some of you to review my spec to see if there are mistakes or better options. I'm very open to suggestions.. I'm becoming spiritual like Nelson
Mark
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@ Projects by Fanatics , for Fanatics
Thanks to Mr Pass , Variac , 6L6 , Jason and all DiyAudio Store Team.
No doubt this Vfet kit become in the future legendary 21 century DIY evenement.
I feel honoured and happy to can build this amplifier.
Wish you received them quickly like my....Hoouuray !!!!!
Immediatly start to search for candidates with low ppm to go
step 1 resistors stuffing procedure and tests voltages like in Vfet P2 Draft article.
For the moment at my fiver i do match , verify resistors values.
Have a nice sunday
Thanks to Mr Pass , Variac , 6L6 , Jason and all DiyAudio Store Team.
No doubt this Vfet kit become in the future legendary 21 century DIY evenement.
I feel honoured and happy to can build this amplifier.
@ Ernesternest & Diyers
Wish you received them quickly like my....Hoouuray !!!!!
Immediatly start to search for candidates with low ppm to go
step 1 resistors stuffing procedure and tests voltages like in Vfet P2 Draft article.
For the moment at my fiver i do match , verify resistors values.
Have a nice sunday
Attachments
jftr, it took me a while to find them again in the depth of the messy shelf : ) but you are totally right, it´s the 2SJ28 one could get at Circuitdiy and of what i´ve 4pcs.
stefan