[BoilermakerFan]

Quote:

Originally Posted by nano_machine /img/forum/go_quote.gif Has anyone tried building this with this with 6DJ8/6922's at 24V? 6GM8's are getting so difficult to find.

The tube buffered gainclone runs a 6922 at 35V and the chip at 24V so I suspect the sound quality suffered at 24V. Joe didn't specifically say he tested it at 24V, but I'm sure he did as he likes to keep the design as simple as possible. They will sound better at 48V though.

Quote:

Originally Posted by rodentmacbeastie /img/forum/go_quote.gif I am still awating my replacement H-PS-1 board from Tubecad. I am wondering if one of these PS kits is enough to power two boards? I should get another H-PS-1 board right? Any suggestions for a transformer?

One H-PS-1 is enough to run the Aikido 24V board, so it should have the power to run two separate Octal boards and a buffer.


Quote:

Originally Posted by rodentmacbeastie /img/forum/go_quote.gif Would you be able to feed an IRF610 with a LM317 in the buffer? I have some IRF610 from my D1 I/V stage left over znd wondered if they would sound better?

I have the IRF510s and IRF610s to try in my 24V board and plan to run them at 24V with LM317, LT1085, and the 10M45S current sources. However, the bias current resistor changes for the LV regs versus the FET reg.

I will also be testing the IRFZ35 FET from the Millett Hybrid MAX in the Aikido and the IRF510/IRF610 complimentary pairs will be auditioned in the MOSFET-MAX when I build it on the new rev1.2 board.

 

[digger945]

BMF, do you have the newer pcb's with the dual thru holes for both regs and fets?

 

[BoilermakerFan]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif BMF, do you have the newer pcb's with the dual thru holes for both regs and fets?

Why yes, yes I do...

 

[digger945]

^You crack me up, goofball LOL

Thanks I needed a laugh, really.

I guess I will order some of those IRF mosfets and give them a try, see how they sound. While I was ordering H-PS-1 stuffs,I also ordered some extra LM350's and LT1085's to try.

Anybody got any links to cheap/on sale xfmr's? <for the 6H30 - 150V@120+mA and 6.3V@4A minimum.
I will prolly go with Digikey/Mouser Hammond stuff, can't argue with the price, though they are almost all labeled with the "BIG" stamp, so extra shipping.

 

[BoilermakerFan]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif ^You crack me up, goofball LOL Thanks I needed a laugh, really. I guess I will order some of those IRF mosfets and give them a try, see how they sound. While I was ordering H-PS-1 stuffs,I also ordered some extra LM350's and LT1085's to try. Anybody got any links to cheap/on sale xfmr's? <for the 6H30 - 150V@120+mA and 6.3V@4A minimum. I will prolly go with Digikey/Mouser Hammond stuff, can't argue with the price, though they are almost all labeled with the "BIG" stamp, so extra shipping.

I typed it in an Austin Powers voice too.

You can use transistor sockets and 3/8" standoffs as spacers for threaded heatsinks to make swapping easier. That's what I'll be doing on all three MAXes and the Aikido. It adds some costs to say the least, but it will save a ton of time and limit the risk of lifting a trace so I think it is worth it. Initially I'll use the same heatsinks as my MAX builds on the Aikido, for the FETs, then I'll set them up on the bigger Aikido 'sinks once I find the set I like the best.

Antek has 150V toroids with 6.3V and 12.6V taps. Price is definitely better at Antek than Digi or Mouser. I plan to order a 150V and 200-250V toroid for the Aikido when I order all my other transformers to minimize shipping since Antek is $10 flat rate.

 

[digger945]

I can't seem to find a bloody good tranny socket for me TO-220 stuffs

LOL.
I'll take your suggestions(on the socket), price is of no concern. The heatsinks I have already got 3 verticle holes for 3 different device mounting heights. I have seen these on an Aavid datasheet from a link on Mouser earlier today but can't remember what exactly I was looking at or looking for. It will be a booger to get all the solder out of the holes to mount sockets as these pcb's are so thick. I finally gave up when I mounted the 2540's and just mounted the device in the top hole on the HS and cut the legs off so they were just a little shy of the pcb (when the HS was re-mounted), then touched the legs with a little solder first and it soon wicked up from the pcb.

Hey thanks for pointing me back to AnTek, I had looked at that traffo before and didn't notice that it has plenty of 6.3V current for my build, and the most attractive part, only like 29 bucks, how could you go wrong. Perfect

thanks again(Austin?), this will save me a ton of dough(for sockets maybe?).

 

[MisterX]

http://media.digikey.com/photos/Molex/10-18-2031.jpg

Part # WM2551-ND

 

[digger945]

Cool, thanks yet again Mr. X.

EDIT: Price for one piece at Mouser is less than 100 pcs at Digikey. Still not a bad price either way.

 

[BoilermakerFan]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif Cool, thanks yet again Mr. X. EDIT: Price for one piece at Mouser is less than 100 pcs at Digikey. Still not a bad price either way.

I'll be using the ones Mr. X linked. I paid $1.88 for mine, but I had a lot of other bits on the order, so Digi was cheaper for me overall. I'm not sure if the multi-holed heatsinks will work with the sockets unless they are spaced 3/8" up. I haven't done a trial fit on my PCBs though. I know the heatsinks for the 24V Aikido only come with pins, so I have to pull those and tap to 6-32. The MAX 2-1/2" heatsinks are screw mount though.

 

[Coreyk78]

Well since I have too much time on my hands, and I haven't bought most of the components to populate my 24v Aikido board I've been thinking about changing my plans for the build. I have 8 6N23P tubes, basically the Russian 6DJ8 which are designed for ~100V operation. I'm hoping to build this thing once, so I want to try and get the best result the first time.

I already have the H-PS-1 regulator board and an inexpensive 24vct xformer because I was planning to go with 25.2V B+, but I'm wondering if I can change some components to use that for the heater supply. (regulated power for the heaters may be overkill, but I'd like to use the board since I already have it.)

The big thing that I don't yet understand is the best way to get the 100v for the B+. I could build an unregulated power supply using a 36V + 36V xformer series wired to give 72VAC and 100VDC after rectification using a spare Audiosector gainclone rectifier board I already have with MUR860 diodes and some appropriate voltage rated smoothing caps. The thing is most xformers at that voltage are much higher VA rating than I need, and thus more expensive than I need, and I would still need a 2nd low voltage xformer for the heater supply.

The other option I can see is using a xformer designed for traditional tube amps, Antek has a 150v + 150v/ 6.3v + 6.3v xformer, but high voltage stuff is beyond my knowledge right now and I wouldn't know how to reduce that voltage to get it down to 100. And I haven't read the Aikido manual enough to really comprehend how to wire seperate B+ and heater voltages and use the right regulators for the Headamp section and make it all work with the high voltage. I've tried a couple times over the last weekend to figure it out, but its a bit over my head I'm afraid. I think it would be the best performance to run the tubes at 100V but I just don't know how to do it. Maybe I just need to keep rereading the manual until it sinks in instead of thinking out loud on this thread, haha.

Of course there is the other option of just waiting to find some reasonably priced 6GM8 tubes, or just forging ahead with my original plan of low-voltage 6DJ8s and just see how it sounds for myself.

Ugh, too many options has my polish brain spinning, I think I'm more confused on what to do than ever.

 

[digger945]

Corey,
Vacuumtubes.net shows 6GM8's for $20 each.
Nixie Store on ebay shows two pairs of 6N27P's left, buy-it-now price of $48/pair with $8 shipping, not bad me thinks.

On the power supply and/or regulator, I am gonna use the $74 PS-1 as soon as they are back in stock. It is good from 100V - 300V. I'm getting a transformer(both B+ and 6.3V heater secondaries) from AnTek for $29 + shipping.

BMF, I added the TO220 sockets to my Mouser order, I bought 10 so the price was $1.09 each

.

 

[Coreyk78]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif On the power supply and/or regulator, I am gonna use the $74 PS-1 as soon as they are back in stock. It is good from 100V - 300V. I'm getting a transformer(both B+ and 6.3V heater secondaries) from AnTek for $29 + shipping.

Yeah I like the idea of the PS-1, but I'm not really wanting to spend that much more money on the power supply if I don't have too.

When I think about it more I should still be able to use the H-PS-1 @25.2v for the heater supply since they are wired in series, and use another power supply for the 100V B+. I don't know how to design and build my own regulated power supply, since I don't really get how to set up a voltage regulator circuit. However, getting an unregulated 100v wouldn't be too difficult I think if I do it like I suggested in my previous post. That way at least I'm not wasting the 40 bucks I already spent on these 6N23P tubes. I still need to study up more on which regulators to use for the headphone section, looks like IXCY 10M45S should be used with the higher voltage.

 

[BoilermakerFan]

Good deal there Digger. I ordered about 30, so that would have saved me, oh, $20 or so... Oh well, I still didn't need anything else from Mouser at the time.

Corey

IMHO, the PSU is the most critical piece of any component. Sure the Aikido cuts the NOISE in half, but an unregulated supply will also have voltage issues and more. Save money on tubes if you have to, but don't skimp on the PSU. remember, the "stuff" flows downhill and the PSU is at the top of hill, your headphones are at the bottom of the hill. Garbage In, Garbage Out. Use a filtered IEC jack and a regulated PSU for the best possible power. Maybe even consider the $7 bucks in hardware for a ground loop breaker at the star ground point too. Again, MHO, but there are plenty of other areas to cut costs with much lower impact to the sound quality than a poor PSU.

 

[Coreyk78]

Yeah, I suppose you're right BMF, I'll probably be waiting for the PS-1 to come back in stock so I can do high voltage properly.
Still cheaper than dropping $20+/tube for 6GM8s, especially since I'm the kind of guy that likes to have at least 1 spare set for something harder to find like that.

 

[Coreyk78]

I felt like posting an update on my build progress, I have most of my parts gathered for my 6N23P high-voltage 24V Aikido (oxymoron? hehe)

I have my order in for a PS-1 kit and am just waiting for the next set of PCBs to be in stock.

So far I have 3.3uf Solen PPBs that I'm going to bypass with some russian pios and .47uf multicaps for C1 and C3, and some 1uf Solens for C12 and C13. I also got some 2200uf 35V Nichicon HEs for the heater caps, a 33uf 200V Nichicon PW for C11 and some rather huge sized 470uf 200V PWs for C4, they are almost bigger than some 10000uf 50V Panasonics I have. I also have a bunch of nos ERO-Roderstein KP caps in various sizes on their way to me. Resistors are a mix of Holco, Allen Bradley, Ohmite and Vishay, using the high quality ones in the critical positions.
I have an Antek 150-0-150/6.3-0-6.3 toroid in the mail, so I'm close to having all the parts collected.

I forgot to get the heatsinks and FETs on my last mouser order, (doh!) but I need a couple other odds and ends for a different project so I'll get those soon.

I'm still unsure of what voltage I'm going to use for B+, 100V is suggested for 6DJ8s in the manual, but I've been able to email JB and discuss that a little bit, and he said his favorite amp for his HD650s uses a 150V B+ with 6DJ8s.

Being a total high voltage tube noob I look at the 6N23P datasheet and it says 100V anode voltage, but 300V max anode voltage, pretty much the same as 6DJ8. Am I going to shorten the tube life by running somewhere around 150V B+?
Also I haven't seen the manual for the PS-1 yet, but I think it should be able to drop the 300VCT from the transformer to 150VDC without any problems right?

I just want this thing to be done right, I'm spending more money than I had planned to, but I intend to use this for years to come. Now I just need to pick out an enclosure that will do all these parts justice, maybe a Par-Metal 20 series, I don't know yet.