Lovoltech power Jfet groupbuy

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GRollins said:
List your headphones, impedance (if known), and voltage swing desired for your normal listening volume. If all else fails, play a sine into your headphones at a reasonable volume and give me the RMS voltage. We'll multiply that by some reasonable factor to have room for peaks and go from there.
Grey
Okay, I'll bite.
Sennheiser HD580, 300 ohms, 0.2W should give me 120dB - lots of headroom. I make that out to be 7.75VRMS or about +/-11V.
 
Oh dearie, dearie, me...
The floodgates have opened and lemme tell ya somethin'--the Mongol Hordes could learn a thing or two from DIY folks hungry for JFETs.
Okay, a little housekeeping. I'm getting e-mails that aren't including the basic info I requested:
1) Your DIY userid
2) Your real name
3) Your address
4) How many devices you want
5) Matched or unmatched
I even had one that was just a name, but none of the other info. No quantity, no address, nothing.
Sigh.
I've put the baby down for a nap (that's a joke, son, two year-olds don't sleep...ever) and am going to try to get a few e-mail replies out. I will attempt to get to everyone who has ordered so far, but don't panic if it's a little later in the day, or perhaps even tomorrow.
I'm fine on stock. You want 'em? Send me an order. I don't anticipate running out until 5 this afternoon. (That was another joke. Don't panic. I bought plenty.)
I've had an order from Indonesia and one from Australia. Technically, I'm not handling orders from that corner of the globe. I'm doing North America (Mexico, US, Canada) and David Briggs (dhole) is doing Europe. No one else has stepped forward to handle other areas yet. Now, if it doesn't get any worse than one order each, I may go ahead and deal with it, but I've always had the impression that Australia had more DIYers than the rest of the world combined. With that in mind, I anticipate more Aussie orders.
Let's do this--if you live somewhere other than North America or Europe, go ahead and send me an order. Warning: For the time being, I'm just going to let them pile up. Do NOT anticipate immediate shipment. If someone steps forward to handle a given area, then I'll forward the orders to them. If not, maybe I'll open a bottle of Lagavulin and try to work it through myself. We'll see. One way or another, we'll try to get JFETs to everyone who wants them, even if it takes a while. Sorry, but there's only one of me and I'm running on two hours sleep, which is scant even by my standards.
I've had one fella ask if it was okay if he ordered through a US member (he lives elsewhere in the world). Absolutely! I'm just trying to stay out of all the paperwork and junk involved in shipping overseas. If you live in, say, Peru (say hello to Paddington Bear for me), and have a buddy here in the US, then feel free to make arrangements with them. I'll ship to them, and they can ship to you. If you're happy with that, then it's fine by me.
I'm going to cheat and cut-'n-paste this over in the Market thread to save time. Then I'll get started on the e-mails.
Quick! Somebody fill my glass!

Grey
 
GRollins said:
You want a headphone amp? Cool. I bypassed a design on the way to the one I'm working on now that might work nicely as a headphone amp. How much voltage swing do you need for your headphones?
Anyone else want to chime in on this?
List your headphones, impedance (if known), and voltage swing desired for your normal listening volume. If all else fails, play a sine into your headphones at a reasonable volume and give me the RMS voltage. We'll multiply that by some reasonable factor to have room for peaks and go from there.
Once I get done with a couple of larger circuits, I may back up and take a look at a dedicated headphone amp for Paul (and anyone else) using the other topology.

Grey

Just to be different:

Grado RS2, 32 ohm, 2 VRMS is more than I will ever need.
I guess that doesn't qualify as an amp, but rather as a buffer.

/Flemming
 
I've had one fella ask if it was okay if he ordered through a US member (he lives elsewhere in the world).
I guess that would be me, then😀 Thanks a lot, Grey! Just let me know and I will fly over there, and fill your glass, just like Graeme😀 Could even be a happy event😉 I will go ahead then🙂
On a serious note, please answer my previous post:
http://www.diyaudio.com/forums/showthread.php?postid=814529#post814529 Thanks.

Steen😎

BTW. We all understand that the family is first priority, so dont get too stressed by all this. Take your time🙂
 
Stressed???
Who's stressed? Me? Yikes! Everybody knows I'm the calmest guy around. Whatever gave you the impression that I was stressed?
(A gentleman in a white lab coat approaches. In his hand, a short glass filled with amber fluid. "Excuse me, sir," he says. "It's time for your four o'clock medication.")
(A long, heartfelt sigh of relief escapes the patient.)
Stress, I banish thee.
Huh! Why do you think I specified Lagavulin (or Highland Park--a tough choice)? Wine is for drinking when you're already relaxed. This little escapade calls for more serious medicine.
Onwards and upwards, then. I've been weighing things and it looks as though my earlier guess on postage was a little low.
Current US 1st class postage estimate (assuming standard business envelopes):
1-40 JFETs will get by within the 1 oz. limit for a .39 stamp
from there to just shy of 100 will come in under 2 oz. hence a .63 stamp
100 JFETs will tip the scales just over 2 oz. and require an .87 stamp
Above 100, we'll see what works best.

Grey

P.S.: Actually, I'm mainlining Assam (that's highly caffeinated tea, for those who aren't familiar with such things), trying to goad my body a little further along the path.
P.P.S.: Anyone who shows up bearing a decent bottle of single-malt earns an 'atta-boy.' Who needs tea, anyway?
 
Steen,
I have not begun matching yet. I am going to try to get people large blocks of matched devices if they request it, but please, please be reasonable about this, folks. I've only got eight little fingers and two little thumbs and it's not that critical to match devices between channels.

Grey

Another P.S.: I'm taking note of the headphone posts, but it won't happen immediately. Just for giggles, I've already got a pair of the Grado 325s on hand (in addition to some old Yamahas), so I know about the current demand they place on headphone amps. The thing that will be tough (with the aforementioned topology) is voltage swing. After all, we'll have current to burn with these JFETs. I don't think there's a headphone on Earth that we can't handle with a single device (or perhaps a pair going push-pull, which is where I'm headed) per channel. Now, what would be a gas would be to run the JFETs alone, i.e. non-cascoded, but that will be touch and go for voltage swing, even with Grados. With others, it's a non-starter. Doesn't hurt to dream, though. I'll devote a brain cell or two to the problem.
Actually, now that I think of it...
Ah, fooey, let me get back to e-mailing people. I've got a lot to do before I can get back down into the Dungeon.
But still...if you put this here and that there, it might work...
 
I have not begun matching yet. I am going to try to get people large blocks of matched devices if they request it, but please, please be reasonable about this, folks. I've only got eight little fingers and two little thumbs and it's not that critical to match devices between channels.
Fair enough, not to worry🙂

Steen🙂
 
If--and only if--you live in the US, you should have return e-mail from me by now. Given that I'm running on two hour's sleep and lotsa caffeine, double-check my math. If I did it wrong, please accept my apologies and drop me a line. We'll fix it.
Steen, you're included in the US batch. If you and your surrogate have not gotten e-mail, let me know.
I'll be tackling Canada later tonight or (more likely) tomorrow, but first I've got to research postal rates betwixt here and there.
Those from other corners of the globe, sit tight.
I'll be posting this in the other thread as well.

Grey
 
Ello Guys

These are my projected prices for Europe. please respond with youur thougths. Please take into account that I will have to pay VAT Duty and will be adding a small amount for myself. If they are too high and people wont buy them I wont go through with the deal with Grey.

1 = £1.58
20=£1.39
100=£1.29
200=£1.24
1000=£1.21

This price is subject to change ( not by much at all but if postage costs for me are high ... insurance etc)

postage will be at near cost. I will have to see how this works out.

Please give me some feedback. But make it constructive. Yes the prices are higher but ther is a reason for this ( read above)

dave
 
Wiki estimate USD 0,97.
dhole estimate GBP 1,39 = USD 2,46 at 20 pieces,
(based on 1 GBP = 1,77 USD, spotrate jan 14, 2006, kitco.com)

My wiki entry is withdrawn.
If dhole's deal goes through, I am taking 20, at or below this
estimate.
Looking forward to see final details. I hope before end of january
2006, so I can start experimenting.

Maybe it's a good idea to dispose off the wiki all together?

Regards
 
Wiki price means nothing. It may be what Grey is paying I dont know.At the moment I can pay the prices that Grey posted for unmatched parts ( possably 1000 ) So you are paying Grey some and then VAT and Then postage to UK then I am adding the Same percentage as Grey based on Grey getting them for $0.97. This doesnt include postage.
 
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