[InSides]

So,
I am having an F1 built by a friend of mine, and have started gathering the parts. Already got a wonderful encapsulated 500VA transformer for it, all the required electrolytics, and everything else is up to the builder... save the enclosure.

I would like to go with one of the HiFi2000 cases, but I would like to keep it as small as possible while still having the required cooling capabilities.

Question 1: Would the 2U high, 300mm deep case [with heatsinks] be sufficient for the F1? If not, I would not go for the 3U, but rather get the 2U high, 400mm deep, but only if absolutely necessary. Small is beautiful.

Linkage: HiFi2000 2U Heatsink Cases

Question 2: While the amp shall be used mostly with the K-1000, is there a way it can, with proper padding resistors [I hope this is the right phrase] be used to power, say, HD-650? Seeing it is balanced it should do them nicely, if possible at all.

Many thanks.

 

[adamus]

can i suggest you head over to the passlabs forums on Diyaudio.com .

 

[InSides]

Quote:

Originally Posted by adamus /img/forum/go_quote.gif can i suggest you head over to the passlabs forums on Diyaudio.com .

I would, and as a matter of fact, I have, but headphone specific questions get answered here from a wider audience, and general DIY queries have been answered more promptly and more concisely here anyway...

...at least in my experience.

 

[digger945]

Then you would already know that the Firstwatt F1 is a current drive amp, a little different from the usual voltage amplifier.

 

[cfcubed]

Whomever is building the F1 should be able to assist w/heatsink calcs & perhaps change the biasing to lower dissipation to meet the need. If its going to be a headamp exclusively you may not need all the F1's 10 watts/channel to stay in Class A driving the cans.

Perhaps you've seen this thread talking about a DIY F1 driving K1000s. Having built F1 and F2 amps, can say you should be quite pleased w/the amp.

 

[InSides]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif Then you would already know that the Firstwatt F1 is a current drive amp, a little different from the usual voltage amplifier.

Thank you, I was quite aware of this having read the service manual... however, I will not pretend to have understood everything.

To put it simply, would what you imply means that the F1 is entirely unsuitable for driving dynamic headphones other than the K-1000?

Quote:

Originally Posted by cfcubed /img/forum/go_quote.gif Whomever is building the F1 should be able to assist w/heatsink calcs & perhaps change the biasing to lower dissipation to meet the need. If its going to be a headamp exclusively you may not need all the F1's 10 watts/channel to stay in Class A driving the cans.

I actually wanted the standard F1 since the amp would be used mostly for K-1000 driving duty and maybe some Lowthers in the future... maybe.

Usage with a different headphone is just another [not really important to me anyway] option, if possible.

Quote:

Originally Posted by cfcubed /img/forum/go_quote.gif Having built F1 and F2 amps, can say you should be quite pleased w/the amp.

Much appreciated! Will look into the threads.

 

[digger945]

Quote:

Originally Posted by InSides /img/forum/go_quote.gif To put it simply, would what you imply means that the F1 is entirely unsuitable for driving dynamic headphones other than the K-1000?

Well as cfcubed pointed out, someone else has built one and listened to the K1k's using it. I guess like everything else, if you can't borrow it or listen to it at a meet, then you must buy it or build it and listen for yourself to know what, and how, it will sound.

 

[Pyriel0]

I use mine to drive the dx1000. I just ordered a couple 4 and 8 ohm 10 watt resistor pairs and put them across the outputs with a couple Parts-Express.com:*Gold Plated Dual Banana Plug Black | banana plug dual banana speaker connector audio connector binding post You just bend the resistor leads to fit in the holes and then tighten the screws. It has worked fine for me. I use the 4 ohm resistors with the dx1000 because they are high sensitivity and don't need too much power. It makes it so I can turn the volumite on the buffalo up to about the same level as using the K1000 without any resistors.

http://www.mouser.com/ProductDetail/...3xEEqplw%3d%3d the 4 ohm resistors I use
http://www.mouser.com/ProductDetail/...i9%252b%2f0%3d the 8 ohms but I haven't needed to use them yet. I just ordered them at the same time incase I get a higher impedance headphone down the line.