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Old 6th June 2011, 11:54 AM   #131
3GGG is offline 3GGG  Australia
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Nice Approach, they look great
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Old 6th June 2011, 12:32 PM   #132
6L6 is online now 6L6  United States
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Wow. Those are the among the best looking F5 ever made!

Very, very nice.
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Old 7th June 2011, 02:00 AM   #133
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Plexiglass cover, and blue LEDs. Nice touch! LOL........

How are your heatsinks and temps doing? Looks as though the amp board placement doesn't make optimal use of the sinks (i.e., boards not centrally located on the heatsinks).

Great construction!
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Old 7th June 2011, 04:47 AM   #134
anilva is offline anilva  India
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Very nice build. Where did you get the power switch from? I am looking for something like that for my F5....

With one Mosfet per heatsink, I am sure they are running quite cool. With 300VA toroid and heatsinks in a monobloc, you can afford to add another pair of output MOSFETs and run warm.

Cheers.
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Old 7th June 2011, 09:23 AM   #135
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Thank you all for your comments and help and especially NP for its design.

Quote:
How are your heatsinks and temps doing? Looks as though the amp board placement doesn't make optimal use of the sinks (i.e., boards not centrally located on the heatsinks)
I have no thermometer to measure but I can hold my hand forever in the sink. Here in Sevilla (Andalucia) makes a lot of heat. Inside my house at least 30 degrees and was more than 40 º. I put a mosfet heat sink for this reason.
The mosfet is not centered on the sink. There are more heat behind than in front. Surely it would have been better to focus but preferred to have the F5 pcb near the audio inputs and outputs.

Quote:
Very nice build. Where did you get the power switch from? I am looking for something like that for my F5....

With one Mosfet per heatsink, I am sure they are running quite cool. With 300VA toroid and heatsinks in a monobloc, you can afford to add another pair of output MOSFETs and run warm.

Interrupteurs - Audiophonics - Câbles, Amplificateurs et Accessoires DIY

How do I add another mosfet?, what are the benefits?

excuse my English

Br

AL
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Old 7th June 2011, 10:31 AM   #136
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Quote:
Originally Posted by albertob View Post
Here in Sevilla
Damn, i'm good.
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Old 7th June 2011, 11:18 AM   #137
anilva is offline anilva  India
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Quote:
Originally Posted by albertob View Post
Thank you all for your comments and help and especially NP for its design.



I have no thermometer to measure but I can hold my hand forever in the sink. Here in Sevilla (Andalucia) makes a lot of heat. Inside my house at least 30 degrees and was more than 40 º. I put a mosfet heat sink for this reason.
The mosfet is not centered on the sink. There are more heat behind than in front. Surely it would have been better to focus but preferred to have the F5 pcb near the audio inputs and outputs.




Interrupteurs - Audiophonics - Câbles, Amplificateurs et Accessoires DIY

How do I add another mosfet?, what are the benefits?

excuse my English

Br

AL
Thanks for the switch details.

Regarding adding one more pair of outputs, there are quite a few schematics in the F5 thread particularly from zenmod, jacco, juma and others on how to parallel the output MOSFETs. Essentially you need matched N-N-P-P MOSFETs and some including me have used Toshiba MOSFETs.
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Old 7th June 2011, 03:28 PM   #138
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Originally Posted by Zen Mod View Post
Fugly!

That's personal taste. Not too sure that I would have made them transparent.

Have you seen my thread on the Aleph 4 Strictly DIY build.

They are nearing completion now.
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Old 7th June 2011, 04:46 PM   #139
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I'm selling 26 x IRFP244s from International Rectifier that have been through the matching process and are supplied with the data obtained during matching. There are easy pickings for pairs and triplets of 1% matched devices.

£50.00 the lot plus P&P.
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Old 7th June 2011, 05:04 PM   #140
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Albertob
Parralel devices is easy Just source resistor 0.47R and gate resistor 47 R
Es lo mismo dos Mosfets dos 0.47 R dos 47 R

Advantages 2 devices sharing the current (this to keep all Power suply the same)
less heat on each device beter use of heath sink.

2 or more devices hi bias better output on low impedance speakers.Voltagge same.

2 or more devices hi biass hi voltagge just more power out.

But not just as IMO (opinion personal) much beter dinamics and slam from mosfets sound much beter more open and faster only snag maybe even more analitic so if you got bad records sell them on.

It all depends on the heat sink, limit is maybe 50W device. (for standard sinks)
I got big sinks so 200W dissipation whitout problems.

If your sinks are cold you could try to up Bias a bit but I would definetly cek the temperature of the mosfets cases first.

If you have poor thermal coupling between mosfets and sinks the sink stay cold and the mosfet eventualy pop.
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