[Beefy]

Oh god, I hope I haven't sparked a whole round of discussion about new and unnecessary non-tweaks

 

[BoilermakerFan]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif Digi-Key - C2D05120A-ND (Manufacturer - C2D05120A)

 

[pabbi1]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif Oh god, I hope I haven't sparked a whole round of discussion about new and unnecessary non-tweaks

Someone had to do it...

 

[luvdunhill]

Quote:

Originally Posted by BoilermakerFan /img/forum/go_quote.gif

pretty much the only high voltage Schottky I know about. SiC is the new rage anyways, right? (i.e. the new fancy SemiSouth SiC JFETs that Nelson Pass is using)

 

[n_maher]

Another power supply up and running and appearing to work just fine. Power trafo is the 369JX. And I think this picture illustrates perfectly the reason for owning more than one DMM.

 

[sachu]

Just finished populating 2 PSU boards...will finish up the amp boards and then test the supplies..also have a 369JX here so more test points with the 300 series transformer forthcoming in due time

 

[BoilermakerFan]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif pretty much the only high voltage Schottky I know about. SiC is the new rage anyways, right? (i.e. the new fancy SemiSouth SiC JFETs that Nelson Pass is using)

Well, if it's good enough for Papa Pass... So very, very tempting.

 

[runeight]

Yes, those SiC jfets are pretty interesting. They are big jobbies though, but they might be really handy in a very high voltage stat amp. You could get at least 2000Vpp out of them if the rest of the amp's components could stand it. But, such an amp would probably kill someone sometime. I know because a 1kV supply almost killed me many moons ago.

But, back to builds ...

Nate, your filter cap voltage looks like nearly 360V. Is that right? If so, keep an eye on the fets in the PS. It may be that the all 100V zener string is the best way to go.

 

[webbie64]

Quote:

Originally Posted by runeight /img/forum/go_quote.gif No, no changes that I can think of. The amp and ps are pretty well vetted by now and we know that they come up and sound pretty good. Since the amps seem to be very quiet I don't think there is any need to adjust the rectifiers. They are already ultra fast if you get the uf4007s.

Sounds great.

Alright I have a request that may sound lazy but it is simply because I am extremely short on time ATM - family issues (elderly mother and mother-in-law have both had (different) operations in the last fortnight; both out of their respective hospitals for Xmas we hope) plus dramatic work change last week (I work in the state political area and we've changed our leader last week, meaning everything will now be changed - ministers, responsibilities, priorities, etc - and the coming fortnight will be FULL ON).

I wanted to complete my Beta Build during my Christmas break but will not have time to get the parts together (I have the boards for the tube amp).

I am looking for someone to assist me by offering to get the full kit of required parts ordered and out to me in Sydney Australia.

I know it's a big ask but I'm from one of those families that reinforced that if you don't at least ask, you'll never know what's possible (or not)

Please don't clog the thread with any responses. If you are willing and able to help then please PM or email me direct.

Thanks.

Ian

 

[Keithpgdrb]

I really hope this proto team wasnt the only build. I am completely NOT ready to attempt this high voltage project, but I do not want to miss out on this. its perfect for what i want. SO, even If I dont get the parts right away, please sign me up for a board on the next run. I'll have to wait for more feedback on the two designs to decided which to build. I remember in an earlier post that you said the two amps sound nearly identical because of the way the tube is integrated. Looking for some more feedback as people start testing. I'll be running NB sr-lambdas.

 

[sumo-kun]

Whew! Just finished a marathon run reading this whole thread.

I'd first like to say, congrats and thanks for the GREAT work guys!

I'd definitely be interested in the next run of amps. I have a SR303 + SRM313 system and its great but this thread has me intrigued. I was looking at getting an Airbow modded 404 sometime and it would be interesting to see how that sounds

When is a next run expected? I'm in Japan so I'll probably have to some homework to see what parts I can get. It will probably be a tube version... maybe. Are there no listening results from the builds yet?

 

[n_maher]

Quote:

Originally Posted by runeight /img/forum/go_quote.gif Nate, your filter cap voltage looks like nearly 360V. Is that right? If so, keep an eye on the fets in the PS. It may be that the all 100V zener string is the best way to go.

Left to Right those meters are reading:

408mVDC from test point 3 to 4.
359mVDC from test point 1 to 2.
298VDC on the positive rail (across the 10k resistor).

I haven't checked the voltage at the caps yet, it was getting late last night. So today I'll do that and also check the bias side of things.

 

[minivan]

psu report

this is for aussie builder's reference or for someone from country with line voltage 240v.

my line voltage at home is high, around 251-5 v, alex suggested to used the 300v zener strings instead of the 291v zener strings.

transfomer is 369jx for 240v line voltage

my readings are:
line voltage: 251v
secondary: 274 v
t1-t2:359mv
t3-t4:-414mv
t3:-352v
t1:355v
rail:-314, 314
all heatsinks can be touch for long period with no problem.

for some reason, when i first start up the psu, t3-t4 and t1-t2 voltages will drop causing both led to turn off, the voltage of t1-t2, t3-t4 will eventually stablized in about 5 mins. alex suggest me to power up the psu and wait 20 minutes then readjust p1 and p2 to raise t1-t2 ,t3-t4 to 360mv and 410mv, and it's been all good since.


also for aussie builder's info, if you ordered $200 aud worth of goods from mouser , they will give you free shipping.i reckon if you source all the parts including the transfomer you should come very close to $200 aud.

i am currently four 100v 1w zener d041(mouser part: 78-1N4764A-TAP) short for the 300v zener string of my other psu build. i will be grateful if someone have some spares one of those to sell me or order 4 extra of those if they are ordering parts from mouser and resell them to me.

 

[Beefy]

Quote:

Originally Posted by webbie64 /img/forum/go_quote.gif I am looking for someone to assist me by offering to get the full kit of required parts ordered and out to me in Sydney Australia.

Not what you were looking for I'm sure, but I am more than happy to share my Mouser project with you for the PS and SS. You will still need to add a fair few accessories for casing, etc (which you would still probably have to do with a kit anyone else offers) and a power transformer, but most of the work is done.

Exstata PS
Exstata SS

I make no guarantees for accuracy (if we're both lucky, someone might be bored enough to confirm it), or that everything will stay in stock...... but this is exactly what I will be ordering tomorrow, plus a couple of spares of most of the transistors.

Quote:

Originally Posted by minivan /img/forum/go_quote.gif i am currently four 100v 1w zener d041(mouser part: 78-1N4764A-TAP) short for the 300v zener string of my other psu build. i will be grateful if someone have some spares one of those to sell me or order 4 extra of those if they are ordering parts from mouser and resell them to me.

I can order you the zeners as requested...... I just still think it is silly for me to order them from the US, get them in Canada, and then send them to Australia.

There has to be a more efficient way......

 

[minivan]

hi beefy, thanks for the offer to help. i am not planning to buy another $200 aud parts from mouser, it mean i have to pay high shipping fee ($39aud shipping charge) just for 4x 100v zener that cost 26cents. now if someone can send those zener to me in a letter, that mean my postage cost will be just the cost of the stamp and the envelop.