sunn 2000s &nbs

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ernie jr
Junior tube assistant
Posts: 65
(1/21/04 7:47 am)
 sunn 2000s
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 does anyone have the specs or a site to get the specs for the power trans for the sunn2000s model. the one with 4 x 6550's
thanks
ernie
 
coap01
Junior tube assistant
Posts: 79
(1/21/04 9:52 am)
 transformers
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 pt: hammond 278CX
ot: hammond 1650t

here is a cool link that talks about what transformers could be used in different type amps.

www.londonpower.com/hammond/matching.htm
 
ernie jr
Junior tube assistant
Posts: 65
(1/21/04 10:56 am)
 Re: sunn 2000s
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 is 200ma enough current on the b+ for for 120 watts off of 4 x 6550's
thanks
ernie
 
Tiny Daddy
I will work on all amps
Posts: 439
(1/22/04 5:58 pm)
  Re: sunn 2000s
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 No 200mA is not even half of what is required.
 
ganzonimx
Hey get your own solder
Posts: 342
(1/22/04 8:37 pm)
  Re: sunn 2000s
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 ernie

you can approximate the mA needed by calculation:

the 6550 has a max plate dissipation of 35W and a max screen dissipation of 6 W, that makes up total 41W for one 6500, for four 6550 it would be 164W.

Now you have to know the plate voltage. If you use a 400-0-400 PT you can expect something around 560V.

Use the formula P = U x I, resp. P/U = I

164W / 560 V = 292 mA

You have to add the current demand of the preamp tubes (3mA each tube) and probably add some 10% to stay on the safe side. Unfortunately Hammond has no PT listed in that range so you would have to go with the 278CX ore look for a other brand.

As always, I hope I din't mess up th numbers...  

Cris



 
Tiny Daddy
I will work on all amps
Posts: 440
(1/22/04 10:00 pm)
  Re: sunn 2000s
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 That 164 watts is just tube dissipation that gets radiated as heat. There's the other 120 Watts that goes to the speaker so 284 Watts total. Current would be 500mA or so. But you would not have to drive a quad of 6550 to max to get 120 Watts output so one of Hammond's larger transformers with 465mA capability should work.
 
ernie jr
Junior tube assistant
Posts: 66
(1/23/04 7:01 am)
  Re: sunn 2000s
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 thanks guys, that is what i thought. the post with the chart that says which hammond transformers to use with which amp says tho use a 200ma p/t and i did not think that was enough. i found the specs for the 2000s p/t 400-425 ma
thanks again
ernie
 
Tiny Daddy
I will work on all amps
Posts: 441
(1/23/04 8:36 am)
  Re: sunn 2000s
--------------------------------------------------------------------------------
 Which London Power chart are you using? From their "Push-pull amps" chart I paste the following:

120W 1650T 278CX 4x 6L6, EL34, 6550, KT88

The 278CX is the 465mA transformer.
 
latecheet
Junior tube assistant
Posts: 1
(3/5/04 1:19 am)
 sunn 2000s choke
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 What choke whould you use when building a sunn 2000s.

thanks,
latecheet

www.dangpow.com/~sunn/sch.../2000s.jpg
 
ernie jr
Junior tube assistant
Posts: 70
(3/5/04 7:13 am)
 2000 s
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 you would use 2 of the chokes used on the 200 s, in parallel. go to www.triodeelectronics.com and look at their dynaco stuff. the chokes run $9.95 each
good luck
ernie
 
ernie jr
Junior tube assistant
Posts: 71
(3/5/04 12:31 pm)
 200s choke
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 to add to the above,
the choke is 1.5 hen, 55 ohm, 200 ma
ernie
 
ganzonimx
Hey get your own solder
Posts: 425
(3/5/04 5:37 pm)
 Q for T-Dady
--------------------------------------------------------------------------------
 I'm still curios about how calculate the power demand of a given circuit. I posted above a calculation, that was replied by TD:


Quote:
--------------------------------------------------------------------------------
That 164 watts is just tube dissipation that gets radiated as heat. There's the other 120 Watts that goes to the speaker so 284 Watts total. Current would be 500mA or so. But you would not have to drive a quad of 6550 to max to get 120 Watts output so one of Hammond's larger transformers with 465mA capability should work.
--------------------------------------------------------------------------------



TD: Could you explain that a little more? I'm still wondering how to apply that to Kirchov's law of maintaining current within a circuit.

Cris

 
 
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