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Old 26th June 2004, 04:40 PM   #1
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Default For all Gain Clone fans.................

There has been a lot written about the power supply for the Gain Clone amps. Typically they give about 50 watts into 8 ohms per channel. The power transformer recommended is about 300VA.
You will find that the Creek 5350SE amp rated at 85 watts per channel into 8 ohms has a 250 VA transformer ! The amplifier is highly rated and many guys are going really ga-ga over it.

Are we missing something here. If so can the enlightened let us know what gives. Does anyone know what the circuit ( of the 5350SE) looks like?
Does it mean a very high PSRR will also mean that one can get away with not only smaller power supply caps but also smaller transformers ? I find that hard to comprehend if ones needs good performance at the deep end.
Cheers,
Ashok.
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Old 26th June 2004, 05:30 PM   #2
joensd is offline joensd  Germany
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Actually a 160VA transformer would do just nicely for a GC.
At +-35V rails it would only slightly be limited into 4Ohm loads.
For power needs of your GC have a look here.

Commercial manufacturers would sell such an amplifier with the 160VA or even less (the less expensive models).

DIYers like to plan their transformer that it keeps up with every load, can play on a permanent basis, with sine waves on the input and has a safety margin to not heat up.
Also the regulation of a big transformer will be much better.

Most cheap commercial amps loaded with a dummy played at their rated max.output would not play for very long....
I work in the repair business and we repair quite a few commercial amps (Pioneer, Sony, etc.) with defect transformers.
Before I rip such an amp apart and use those transformers in my own projects I usually think twice.

In case of the Creek you can get away with around 200VA roughly calculating for an 8Ohm load so a 250VA is OK.

IMO
Jens
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Old 26th June 2004, 05:43 PM   #3
karma is offline karma  Canada
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there using a high-current, N-channel-only MOSFET power output stage

i cant find anything saying it uses a lm chip. gainclone?

i have used a 40v transformer on my clone with no problems
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Old 26th June 2004, 06:20 PM   #4
Variac is offline Variac  United States
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With a 330 VA transformer you do get better regulation, but it also doesn't cost much more than a 200VA if they are bought new.

I think you are right- one person raises the VA a bit "to be sure"
and the next guy raises it a bit more....

The question comes when you have the transformer already or discover a surplus item. 300VA is certainly much more than you need for 2 channels

I have heard the Creek and it is VERY good IMHO.
I will take my gainclone to his house soon I hope for a comparo
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Old 26th June 2004, 07:46 PM   #5
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Quote:
The amplifier is highly rated and many guys are going really ga-ga over it.

Just my 2 cents.

This Creek 5350 is quite shitty amp,like most amps at it's price.It offers lifeless and not very involving sound.Nowhere near well built GC.Actually it is very far , far away GC even the one passively driven.Not mentioning GC with good preamp.

I stopped reading reviews long time ago.

Bartek
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Old 26th June 2004, 07:49 PM   #6
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Quote:
Originally posted by zygibajt
This Creek 5350 is quite shitty amp,like most amps at it's price.It offers lifeless and not very involving sound.Nowhere near well built GC.Actually it is very far , far away GC even the one passively driven.Not mentioning GC with good preamp.

Bartek

is the above conclusion based on actual listening tests (assuming done reasonably scientifically) or it is based theory?
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Old 26th June 2004, 10:12 PM   #7
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Thumbs down Don't believe the hype

Guys, don't judge what you don't know, what you haven't heard.
Reading magazines is amuzing, but don't take those guys too serious.
I've been shocked too many times with much raved products.

Now... the GC sounds better with 1000 to 1500uf capacitance per rail.
That's why you need a big trafo.
This is very low capacitance for the standards of a 50w amp, and you can't do anything without mucking up the sound.

Well... actually you can.
If you regulate, you can use as much capacitance as you want before the regs, and IMHO you can use a smaller trafo.
And you'll get better sound.
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Old 26th June 2004, 11:24 PM   #8
netgeek is offline netgeek  United States
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How about some measurements and 'scope photos....?
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Old 27th June 2004, 03:38 AM   #9
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Default Regulated supplies..........

1. With very small supply caps , the supply impedance would be higher. Ripple would be higher and the effective DC of the power supply would swing up and down with the fluctuating load current particularly at lower frequencies.

2. With a regulated supply , the supply impedance will be very low , and there would be practically no ripple and DC voltage should be as steady as a rock ( just about ).

3. With a very large supply cacacitor the supply impedance will be low , the effective DC of the power supply will be far more stable than (1) and ripple will be much less.

So why does (1) sound as good as it it supposed to ?
Why does (2) sound even better than (1) when it is an extreme case of (3).

Does anyone have any plausible explanation ? Is it possible to see the effects of the supply on the music signal, like transients etc , when used with a real load. There has to be some meaningful explanation for the differences that people have heard. Has anyone got any scope shots as visible proof of the differences.
Cheers,
Ashok.
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Old 27th June 2004, 04:18 AM   #10
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Quote:
is the above conclusion based on actual listening tests (assuming done reasonably scientifically) or it is based theory?
It's based on listening to that amp for a couple of months and comparing it to many other ones.
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