I think an SE transformer in parafeed would be lovely for headphones 🙂
Everyone sit tight for now. Maybe I need to get a Google form together to gauge interest for testing? The initial prototype boards I've ordered is just ten noval and ten octal/seven pin boards, and I plan to build off one of each. That leaves nine of each that I'll happily send along to willing testers. However, I'm not sure the best way to handle the logistics, pricing, etc. I'm also not sure how much we can go into the details before a marketplace thread needs to happen. What would be a fair price per board? A flat rate envelope or box is ~$7 or so shipped within the continental united states', but there's also a good bit of international interest as well- which in recent experience can get pricy fast.
I'd appreciate some insights from someone that is more experienced in this matter. I don't want to commit to something that will get me overwhelmed.
Everyone sit tight for now. Maybe I need to get a Google form together to gauge interest for testing? The initial prototype boards I've ordered is just ten noval and ten octal/seven pin boards, and I plan to build off one of each. That leaves nine of each that I'll happily send along to willing testers. However, I'm not sure the best way to handle the logistics, pricing, etc. I'm also not sure how much we can go into the details before a marketplace thread needs to happen. What would be a fair price per board? A flat rate envelope or box is ~$7 or so shipped within the continental united states', but there's also a good bit of international interest as well- which in recent experience can get pricy fast.
I'd appreciate some insights from someone that is more experienced in this matter. I don't want to commit to something that will get me overwhelmed.
Would this be ok? AS-05TC300 - 50VA 300V Transformer - AnTek Products Corp
I'd go with 100VA or 320V, but for some reason those to out have 5V tap for a rectifier only 6.3V tap. I am not sure if it is a good idea to drop it with a resistor.
You can drop with a resistor but I wouldn't, I'd rather source a 6 volt rectifier or go solid state. I've got an extra EZ81 around here somewhere I may use for one of my builds.
There are some 6V rectifiers, of at least 6CA4 capacity. Then there are the singles, aka damper diodes.
Even the lowly 6W4 pair is more than capable... 🙂
cheers,
Douglas
Even the lowly 6W4 pair is more than capable... 🙂
cheers,
Douglas
i already did that. but i tried to explain other causes of noise, and just getting sick and tired being jumped here...
😎 They came!
Biggest cap I have on hand are these fancy-pantsy Jantzen "Superior z-caps" in 1200 volt, 0.15uF. a little lead bending and they fit well. Sockets all go right on, boards look nice! I'll try to dig out the stuff to start populating a couple in the next few days. Overall impressed with how they look, much smaller than I imagined now that I have them in hand. Should be good for compact little builds 🙂
Biggest cap I have on hand are these fancy-pantsy Jantzen "Superior z-caps" in 1200 volt, 0.15uF. a little lead bending and they fit well. Sockets all go right on, boards look nice! I'll try to dig out the stuff to start populating a couple in the next few days. Overall impressed with how they look, much smaller than I imagined now that I have them in hand. Should be good for compact little builds 🙂
Attachments
I think I need to order some parts before I can do much to them, I'm not into super fancy-pantsy audiophile specific parts, so I think I'll grab a set of these for output caps, cheap and they will fit the board-
MKP1G036806B00KSSD Mouser
MKP1G036806B00KSSD Digi-Key
Mainly posting it here as reference for others, but I hear good things about the MKP 10 series capacitors for audio.
The only higher voltage film caps I have on hand are the Jantzens but they are a bit lower capacitance than I would like to use here, .47uF, .68uF, or up to 1uF are more what I would want. I suppose I could use some "for now" and swap them later.
I have all the smaller parts/components I think, I'll just need to order some plate resistors as it looks like I only have low values or low watt types that wont work onhand.
MKP1G036806B00KSSD Mouser
MKP1G036806B00KSSD Digi-Key
Mainly posting it here as reference for others, but I hear good things about the MKP 10 series capacitors for audio.
The only higher voltage film caps I have on hand are the Jantzens but they are a bit lower capacitance than I would like to use here, .47uF, .68uF, or up to 1uF are more what I would want. I suppose I could use some "for now" and swap them later.
I have all the smaller parts/components I think, I'll just need to order some plate resistors as it looks like I only have low values or low watt types that wont work onhand.
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For a few more dollars there is a wima true foil capacitor too FKP series:
https://www.mouser.com/ProductDetail/WIMA/FKP4J036807G00MSSD?qs=dTJS0cRn7ogcml4U6CqycA==
https://www.mouser.com/ProductDetail/WIMA/FKP4R036807H00KYSD?qs=OiDNLlGUHG0bzfyJRc9Nbw==
Those higher volt ones don't drop in to the board (they have a wider lead spacing) but they have ones that do in the 400 volt size, the 1uF is a stocked item, the 0.68uF are not, but close enough and won't hurt to oversize a bit. $3.73 each isn't bad at all.
FKP4G041006J00JYSD
Might grab some of these in 400 volts, I'm not likely to go over 350 volt supply.
FKP4G041006J00JYSD
Might grab some of these in 400 volts, I'm not likely to go over 350 volt supply.
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For those interested - here is a 680nF 630V part that fits and costs 28 cents. CHAMPION|CHAMPION MPP684K0630D312011B2815|Polypropylene Film Capacitors (CBB)|LCSC
I used a 0.68uF output capacitor for coupling to a 120k input KT88 tube amp back then. Choose Cout value for low frequency roll-off no higher than 2Hz with your amplifier's input impedance.
A better value might be 10uF for a 10k load.
I use these: KYET|KYET MKP20106J2EAC461625|Polypropylene Film Capacitors (CBB)|LCSC
I use these: KYET|KYET MKP20106J2EAC461625|Polypropylene Film Capacitors (CBB)|LCSC
Most of my projects are a 100k input so a 1uF would be pretty good for most purposes.
Can the 6V6 gain version reliably drive a 10K input? I have a feeling this may be a little tough for it. Maybe a 6P43P on the noval board would work well for that, or an EL84 or EL86 for the higher gm? Hmmm.
Anybody have resistor choice suggestions at mouser? I was going to order Koa SPR2/5 series but they only carry like four values on them there 🙂
Can the 6V6 gain version reliably drive a 10K input? I have a feeling this may be a little tough for it. Maybe a 6P43P on the noval board would work well for that, or an EL84 or EL86 for the higher gm? Hmmm.
Anybody have resistor choice suggestions at mouser? I was going to order Koa SPR2/5 series but they only carry like four values on them there 🙂
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