From Nelson Pass's ZenV8 article:AudioFreak said:
"Last but not least, JFETs are not sensitive to static discharge"
Brilliant!
Now Mark, I assume a tube of these is ~ 30 devices give or take a few ..... that being the case, I'll take a tube.
Now Mark, I assume a tube of these is ~ 30 devices give or take a few ..... that being the case, I'll take a tube.
Dan,
A tube is 75 devices.
As far as I'm concerned, you're welcome to any quantity from 1 to a zillion, but Mark may have other restrictions.
Grey
A tube is 75 devices.
As far as I'm concerned, you're welcome to any quantity from 1 to a zillion, but Mark may have other restrictions.
Grey
Thanks Grey,
So either they are closer in width to something like a IRFP610 than they are to something like an IRFP240 or the tube is 6ft long....
In any case with that news in hand, I'll go for a neat 2 dozen assuming that is ok with the guys running this.
So either they are closer in width to something like a IRFP610 than they are to something like an IRFP240 or the tube is 6ft long....
In any case with that news in hand, I'll go for a neat 2 dozen assuming that is ok with the guys running this.
Dan,
They're about 1/4" wide--even smaller than a TO-220 case.
A tube of 75, with end plugs and stuff, is 20" long.
They're tiny little fellers, which is what makes it challenging getting the heat out of the device. On the plus side, if you follow Nelson's recipe in the Zen #8, you'll only be dropping about 2W per device, so it's not as intimidating as trying to dissipate 25 or 30W from a TO-220 or TO-247. I've been doing something similar to what was posted earlier--I think by grataku in this thread--but have two other ideas in mind that I'd like to try once the dust settles from the buy.
To all,
I've been sidelined for the last two days by external factors, so I haven't gotten much accomplished. I hope to get back to the matching game tomorrow. I had originally intended to "work ahead" on the matching so as to be ready when everyone's checks cleared the bank and it was time to ship. I'm not behind yet, but my buffer of days is eroding.
No, I don't have an answer yet on how large matched groups can be. For the time being, continue thinking in terms of 12 or less. You can have as many 12s as you like, but just try not to ask for larger single groups until I've got a better sense of how this is going to work out.
Harrumph...I'd settle for the power staying on...we've been having ferocious wind for the last few days and trees keep falling on the power lines. (Including a few tornados--fortunately not here.) We've lost power numerous times since this past weekend. Supposedly the wind will die down tonight.
Grey
They're about 1/4" wide--even smaller than a TO-220 case.
A tube of 75, with end plugs and stuff, is 20" long.
They're tiny little fellers, which is what makes it challenging getting the heat out of the device. On the plus side, if you follow Nelson's recipe in the Zen #8, you'll only be dropping about 2W per device, so it's not as intimidating as trying to dissipate 25 or 30W from a TO-220 or TO-247. I've been doing something similar to what was posted earlier--I think by grataku in this thread--but have two other ideas in mind that I'd like to try once the dust settles from the buy.
To all,
I've been sidelined for the last two days by external factors, so I haven't gotten much accomplished. I hope to get back to the matching game tomorrow. I had originally intended to "work ahead" on the matching so as to be ready when everyone's checks cleared the bank and it was time to ship. I'm not behind yet, but my buffer of days is eroding.
No, I don't have an answer yet on how large matched groups can be. For the time being, continue thinking in terms of 12 or less. You can have as many 12s as you like, but just try not to ask for larger single groups until I've got a better sense of how this is going to work out.
Harrumph...I'd settle for the power staying on...we've been having ferocious wind for the last few days and trees keep falling on the power lines. (Including a few tornados--fortunately not here.) We've lost power numerous times since this past weekend. Supposedly the wind will die down tonight.
Grey
Thanks Grey..... Just to be clear, these are the same devices as Nelson has used in his latest creation? That being the case as I assume it is and given that it appears that you will be supplying the devices to Mark, I'll put in for 2 sets of 12 matched devices if that's ok.
2 x 12, matched. Roger, roger. (To be uttered in metallic, robotic tones) I'll make a note, but be sure to tell Mark so that he can tell me again, because I'm running on three hours sleep and I can't guarantee that I'll remember anything we've said five minutes from now.
Oh...yeah...same devices.
Grey
Oh...yeah...same devices.
Grey
Dan, Australia, and nearby country’s.
Could you please send me an Email with your requirements so that I don't need to track this thread. Also could you include Email address, diyaudio name, real name and postage address.
Grey,
Are you happy to supply matched over the pond? And could someone please link me up with the matching procedure.
Could you please send me an Email with your requirements so that I don't need to track this thread. Also could you include Email address, diyaudio name, real name and postage address.
Grey,
Are you happy to supply matched over the pond? And could someone please link me up with the matching procedure.
Nelson started a thread not too long ago about matching JFETs. I posted in it a few days back so it shouldn't have sunk too far down in the list.
Basically it goes like this: Your rail is 3V. That goes to the Drain. Gate goes to ground. Source connects through a 1 Ohm, 2 or 3W resistor to ground. Read the voltage across the resistor.
Grey
EDIT: Yes, I'll send matched devices to anyone.
Basically it goes like this: Your rail is 3V. That goes to the Drain. Gate goes to ground. Source connects through a 1 Ohm, 2 or 3W resistor to ground. Read the voltage across the resistor.
Grey
EDIT: Yes, I'll send matched devices to anyone.
IMPORTANT: PLEASE READ IF YOU ARE ORDERING FROM CANADA
Without warning, my bank is charging a $16.75 fee for processing checks from Canada. This is a flat fee, regardless of the amount of the check. They say that it is a fee imposed on them by the Fed and that there's nothing they can do about it.
I have expressed great displeasure at having this sprung on us with no warning.
I don't yet know about Mexico, but checks from other countries will be more. It will probably be cheaper to do a wire transfer.
If you have not yet sent me a check, then add $16.75 to the total. Since this is a flat rate addition to the amount, you might consider stocking up and writing one larger check, but that's not my decision to make; it's yours.
Man, I'm peeved.
I'm in a time crunch, I'll try to get back in here later.
I'll cut-'n-paste this to the other thread.
Grumble.
Grey
Without warning, my bank is charging a $16.75 fee for processing checks from Canada. This is a flat fee, regardless of the amount of the check. They say that it is a fee imposed on them by the Fed and that there's nothing they can do about it.
I have expressed great displeasure at having this sprung on us with no warning.
I don't yet know about Mexico, but checks from other countries will be more. It will probably be cheaper to do a wire transfer.
If you have not yet sent me a check, then add $16.75 to the total. Since this is a flat rate addition to the amount, you might consider stocking up and writing one larger check, but that's not my decision to make; it's yours.
Man, I'm peeved.
I'm in a time crunch, I'll try to get back in here later.
I'll cut-'n-paste this to the other thread.
Grumble.
Grey
Power resistors
Hang in there Grey!!
Question for anyone/everyone. Is it OK to use wirewound resistors that are NOT noninductive to replace the lightbulbs?
Thanks
Hang in there Grey!!
Question for anyone/everyone. Is it OK to use wirewound resistors that are NOT noninductive to replace the lightbulbs?
Thanks
GRollins-
Basically it goes like this: Your rail is 3V. That goes to the Drain. Gate goes to ground. Source connects through a 1 Ohm, 2 or 3W resistor to ground. Read the voltage across the resistor.
------------------------------------------------------
Mr Rollins thank you Sir....
Basically it goes like this: Your rail is 3V. That goes to the Drain. Gate goes to ground. Source connects through a 1 Ohm, 2 or 3W resistor to ground. Read the voltage across the resistor.
------------------------------------------------------
Mr Rollins thank you Sir....
Today seems to be one of those days when everything goes wrong.
I just received a phone call wherein I was informed that a well-meaning person has done great harm to my entire record keeping system for the JFET buy. I won't know how bad the damage is until I get home tonight.
Reconstruction will take time and will eat into the hours I had allotted for device matching, etc. I have backup files but they aren't 100% current, as the JFET buy has been moving rapidly.
Oh, crap.
My mantra these days, oft-repeated: Be patient.
Grey
I just received a phone call wherein I was informed that a well-meaning person has done great harm to my entire record keeping system for the JFET buy. I won't know how bad the damage is until I get home tonight.
Reconstruction will take time and will eat into the hours I had allotted for device matching, etc. I have backup files but they aren't 100% current, as the JFET buy has been moving rapidly.
Oh, crap.
My mantra these days, oft-repeated: Be patient.
Grey
Grey, this is very very nice of you for willing to spend your precious time doing this service for us!
Thanks thanks thanks...
I am wondering whether I am too late into this GB thing? Can I get 4 matched sets of 10 each?
I am not in a hurry so you can just put me at the bottom of your priority list. 🙂
Thanks thanks thanks...
I am wondering whether I am too late into this GB thing? Can I get 4 matched sets of 10 each?
I am not in a hurry so you can just put me at the bottom of your priority list. 🙂
How about a postal money order in US$ for Canadians???
Would that work?
Cost less than $16 for sure.
Would that work?
Cost less than $16 for sure.
There is no 'too late'...at least until I run out of devices and that won't happen for a bit.
Hit the e-mail button at the bottom of this post and send me:
1) Your DIY userid
2) Your real name
3) Your mailing address
4) How many you want
5) Matched or unmatched
A post in this thread does not qualify as an order, only a direct e-mail to me counts as an order.
Please note that matched devices take a little longer as I've got to get the little fellows out and torture them, make them tell me all their secrets.
Grey
Hit the e-mail button at the bottom of this post and send me:
1) Your DIY userid
2) Your real name
3) Your mailing address
4) How many you want
5) Matched or unmatched
A post in this thread does not qualify as an order, only a direct e-mail to me counts as an order.
Please note that matched devices take a little longer as I've got to get the little fellows out and torture them, make them tell me all their secrets.
Grey
loudandclear,
My understanding is that anything that has to transact across the border is subject to this charge. The more I think about it, the more it irritates me. I do not buy that it costs the Fed. $16.75 per transaction to move money back and forth across our common border. This strikes me as a rather blatant attempt by the government to make money by, effectively speaking, taxing individual transactions between our two nations.
This is free trade?
Grey
My understanding is that anything that has to transact across the border is subject to this charge. The more I think about it, the more it irritates me. I do not buy that it costs the Fed. $16.75 per transaction to move money back and forth across our common border. This strikes me as a rather blatant attempt by the government to make money by, effectively speaking, taxing individual transactions between our two nations.
This is free trade?
Grey
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