advice on Clementine build

[fiftyfivefilms]

Hi Kirk,
The AS-2T300 should be fine you have 330ma of main current and have 2 x 6v 4A of current so you should be able to run tubes up from 6L6GB to KT150.
Made a mistake of specifying my Hammond PT which is not 650-0-650 but is 650VCT = 325-0-325 I can run all the tubes I mentioned above, have also run KT120 on the 300-0-330 smaller Hammond PT without issues and could also run KT150, both transformers have the current capabilities to run all those tubes not at their max power output mind you, but sounding very good without pushing them to hard which to me gives a more relaxed and dynamic sound, having very sensitive speakers I do not require a lot of power I have yet to go over 0.6 watt max. while pushing well over 100db.

Hi, After placing my order and punching my chassis, Antek notified me that the AS-2T300 is not available,....I may be able to squeeze a AS-4T320 into my Chassis, is there any reason not to go with it? Heres a quick link: http://www.antekinc.com/details.php?p=710
Cheers,
Kirk

[Shannon Parks]

Kirk, I couldn't download the datasheet on that model, but since it's rated for so much more power the actual output will be much higher than the rated voltage (which takes into consideration the 0.63A load and DCR losses). The main consideration in the Clementine power supply is the 450V rating of the power supply caps. A CL90 can help at start-up, but this tranny could end up stressing things.

Shannon

[fiftyfivefilms]

Shannon,
Thanks for you reply,,,sadly I already order it. I posted this quandary on another board ( audiokarma) and the general feeling was it was ok...I have some CL-90's for the incoming A/C supply. I contacted Antek for the spec sheet...I'll post that as soon as I receive it...
Thanks Again
Kirk

[fiftyfivefilms]

Kirk, I couldn't download the datasheet on that model, but since it's rated for so much more power the actual output will be much higher than the rated voltage (which takes into consideration the 0.63A load and DCR losses). The main consideration in the Clementine power supply is the 450V rating of the power supply caps. A CL90 can help at start-up, but this tranny could end up stressing things.

Shannon

Hi Shannon...I should have waited for your advice before ordering ( like I said earlier, Antek had a lower voltage model listed as in stock but after ordering and paying they got back to me a few days later with the bad news it wasn't available, in the meantime I punched my chassis in anticipation, I was trying to make the aesthetics of this amp a priority) I could bit the bullet and return the Antek and go with the Dynaco,

...however I found these 500V rated caps a Mousser,594-MAL215959121E3, here a quick link,
http://www.mouser.com/ProductDetail/Vis ... bNSw%3d%3d

would increasing the voltage 50V be enough?

BTW I'm using a 2H Choke from Transendar,,,and am thinking about a Dynaco C-354 as a second choke.

Cheers,

Kirk

[Shannon Parks]

I wouldn't worry just yet - let's see how it plays out. Just monitor the B+ at the choke with the standard caps (using a DMM) and see how it ends up. The stock caps should ideally not have issues with an initial surge voltage to 500V. Regarding the 6.3VAC, just run your filaments off of one tap and it should be well loaded.

Shannon

[fiftyfivefilms]

Kirk, I couldn't download the datasheet on that model, but since it's rated for so much more power the actual output will be much higher than the rated voltage (which takes into consideration the 0.63A load and DCR losses). The main consideration in the Clementine power supply is the 450V rating of the power supply caps. A CL90 can help at start-up, but this tranny could end up stressing things.

Shannon

Hi Shannon,
I received my transformer from Antek ad have a couple questions concerning hook up. Tom McNalley is using an Ankek and his thread ("Friday night date with a chubby) is really helpful but my transformer has additional wires:
I've uploaded a hand corrected schematic ( as you know the PDF is undownloadable on the Antek site).
1. The grey 70V wires? do I just cap these off?
2.One yellow 330v goes to J5- #1
3. One White 0V goes to J5-#3
4. The other yellow 330v and White 0V are tied together on the ground pad near J5 ( this appears what Tom did on his, is this correct????)

5. I'm only going to use one set of the heater wires Blue/ Green and tie off the other two..( forgot to correct the diagram but the heaters draw 4 amps)

One final thing, my transformer came wrapped with a clear plastic covering...do I remove this?

Again thanks for your time I know how busy you are!

Cheers,

Kirk

[Shannon Parks]

1. The grey 70V wires? do I just cap these off?
2.One yellow 330v goes to J5- #1
3. One White 0V goes to J5-#3
4. The other yellow 330v and White 0V are tied together on the ground pad near J5 ( this appears what Tom did on his, is this correct????)

5. I'm only going to use one set of the heater wires Blue/ Green and tie off the other two..( forgot to correct the diagram but the heaters draw 4 amps)

One final thing, my transformer came wrapped with a clear plastic covering...do I remove this?

No prob!

1) Yep.
2), 3) & 4) Yes. These two become the Center Tap and connect to ground.
5) Sounds good.
6) Plastic? Do you have a pic? I'm sure the Antek users can tell you. No idea is it's packaging or protective.

Shannon

[battradio]

DO NOT REMOVE the plastic film .

[EWBrown]

The "plastic film" is the insulating material for the transformer, it should NOT be removed or otherwise tampered with.

/ed B

[fiftyfivefilms]

The "plastic film" is the insulating material for the transformer, it should NOT be removed or otherwise tampered with.

/ed B

Thanks Guys!...I'll leave it be

DO NOT REMOVE the plastic film .

[fiftyfivefilms]

Hi Shannon,
My hook up has been fraught with problems, Tom was advising me on the Antek as he has used one on his Clem (Slightly different model) and is helping me getting them into series. My confusion started in finding the two wires for the center tap.
1. I located what I thought was the correct pair,slowly ramped it up on my variac (no tubes)...@ 90V the fuse blew (1.5 amp) the B+ at the choke was about 315v...thinking I had mis-wired I reconfigured the center tap wires and started again.

2. this time at 20V the primaries at CL-90 started overheating and smoking...( BTW I'm using a Cl-90 on each leg of the incoming A/C) So I shut it down immediately.

3. I came inside, checked my email and Tom had posted a new entry to clarify on how to locate the pairs for the center tap. Find the pairs with no continuity between them, twist them together,using low voltage (10V) test the other leads to see if each configuration add's or subtract's voltage , this now makes sense to me so I go back to the shop to try again

4. But I now I have continuity between all 4 yellow/white wires. How can I locate the correct two wires to use as center taps? Is it possible this PT can't be configured to use a center tap?

5. Did I destroy the PT with my missteps?....

6.Next with all four white/yellow wires disconnected from the board flying free, I test them, they are right on at full voltage, 330 A/C White to Yellow, each pair seems fine and the filaments are 6.3

7. So do you think I destroyed the PT?..

8. Any advice on proceeding?.

Thanks for your help, sorry to be such a pain,...my build looks great!..I bent up my own chassis and had it electro-coated!..I could just get a Dynaco PT but my build would look a little funky, or I could try another Antek?....I'm so far into this now whats another couple $$$

Kirk

[Shannon Parks]

What are your actual resistance measurements between the yellows and whites?
For example:
one set- yellow to white 20 ohms
second set- yellow to white 20 ohms
yellow (first set) and white (second set) 1Megaohm

It seems that the fuse did it's job. You had a dead short on the secondary. I think your transformer should be OK.

Shannon

[fiftyfivefilms]

What are your actual resistance measurements between the yellows and whites?
For example:
one set- yellow to white 20 ohms
second set- yellow to white 20 ohms
yellow (first set) and white (second set) 1Megaohm

It seems that the fuse did it's job. You had a dead short on the secondary. I think your transformer should be OK.

Shannon

Thanks Shannon, hope you can make sense of this, I numbered each wire. Yellow#1, Yellow #2, White #1, White #2

Yellow#1-Yellow#2= 7.6 ohms
White #1- White#2= 27.6 ohms

Yellow#1-White #1= 16.8 ohms
Yellow#1- White#2= 18.1 ohms

Yellow#2- White#1= 16.4ohms
Yellow#2-White#2= 18.5 ohms

Cheers and thanks!

Kirk

[TomMcNally]

Kirk -

Sorry to hear of your troubles. I used a little 330 ma 9 volt wall wart, using the Variac may be too much current for testing. I also only tapped the wires together, I didn't twist them. I just checked another transformer, I get 74 or so yellow<>white on each winding, and like 3 megs winding to winding. If you have an auto-ranging meter, are you sure it's not in "megohms" ?? Just a thought.

[fiftyfivefilms]

Kirk -

Sorry to hear of your troubles. I used a little 330 ma 9 volt wall wart, using the Variac may be too much current for testing. I also only tapped the wires together, I didn't twist them. I just checked another transformer, I get 74 or so yellow<>white on each winding, and like 3 megs winding to winding. If you have an auto-ranging meter, are you sure it's not in "megohms" ?? Just a thought.

Tom,
No worries, no I don't have an auto-ranging meter..but I was impulsive on getting going!, the worst that can happen is I'll get a Dynaco PT if necessary. Shannon is getting back to me about the readings on the resistance I took... there is a chance it is still ok.

Just one question though on the primaries, they are paralleled right?.. red with red and black with black...

cheers,
Kirk