yoshida, that is quirky and lovely at the same time and also showcases the meticulous details inside. Bravo!
BK
BK
Reversing one of the fans might cause some short circuiting of the air. Air drawn out by one fan is then turned around and then sent straight back into the box by the other.
I am not sure how much the side plates are acting as heat sinks and drawing away the heat from the bottom plate but by spacing them with washers reducing contact with the base plate may reduce this affect.
May be a few more holes in the base plate would be better.
Just my thoughts.
I do like the build though.
Tony
I am not sure how much the side plates are acting as heat sinks and drawing away the heat from the bottom plate but by spacing them with washers reducing contact with the base plate may reduce this affect.
May be a few more holes in the base plate would be better.
Just my thoughts.
I do like the build though.
Tony
It is the arrangement we use at work with test equipment, on 24/7 no probs, gets hot without the fans though 🙂
This is probably minimal, due to the discharge velocity of the fan. I would be concerned only if the fans were moving very slowly.
... Just add a few washers to make space around the lid and the air will have lots of ability to move and exchange. No fan reversal necessary.
This is my F5, there are many like it...
I built this amp to go between an Audio Research LS3 and a pair of Altec Model 19s. The LS3 has way more gain than it needs (18dB) and the Model 19s can play more than loud enough with little power (99dB/watt). It seemed like the 15dB of gain and 25watts of power would not be a problem. So far they've been a good match.
I pretty much went with the build guides from 6L6 and JojoD818 which is why it looks pretty much like your standard build I guess. However following the guides seemed the best way of assuring the build would be successful. I'm very happy with the results. Despite being only 25 watts it drives the 19s with more authority than the Dynaco Mark III clones I built for them last year and those measured out at just over 60 watts each.
The boards and F5 parts kits came from the DIY Audio Store. The jfets came from Punkydawg on ebay. They were perfectly matched per my DCA75 and the amp biased up easily, no fuss at all. The chassis is the Deluxe 4U. From the temperatures I'm seeing anything smaller would probably need a fan. The transformer is the Antek 500VA model. It took a lot of space so instead of cramming everything into the bottom I mounted the cap board on the front. I ran the DC wires out the top and laced them down so they wouldn't rub against the lid.
While running the amp in on the bench I did do some testing to make sure I wasn't missing anything. Gain came out to 16dB and matched on both channels. THD+N 1watt/8ohms measured around 0.0089% and S/N for that same condition 85dB in one channel and 86dB in the other. That actually probably represents my test setup more than the amp since redressing and moving cables around could change the result by 2 to 4 dB. BW was a surprise with a -3dB point around 520KHz with no ringing on square waves and stable operation so far.
I think it's a credit to the design that so many people in so many ways can build something that performs that well that easily over and over again. You can see from the photos there is nothing exotic about it at all.
I built this amp to go between an Audio Research LS3 and a pair of Altec Model 19s. The LS3 has way more gain than it needs (18dB) and the Model 19s can play more than loud enough with little power (99dB/watt). It seemed like the 15dB of gain and 25watts of power would not be a problem. So far they've been a good match.
I pretty much went with the build guides from 6L6 and JojoD818 which is why it looks pretty much like your standard build I guess. However following the guides seemed the best way of assuring the build would be successful. I'm very happy with the results. Despite being only 25 watts it drives the 19s with more authority than the Dynaco Mark III clones I built for them last year and those measured out at just over 60 watts each.
The boards and F5 parts kits came from the DIY Audio Store. The jfets came from Punkydawg on ebay. They were perfectly matched per my DCA75 and the amp biased up easily, no fuss at all. The chassis is the Deluxe 4U. From the temperatures I'm seeing anything smaller would probably need a fan. The transformer is the Antek 500VA model. It took a lot of space so instead of cramming everything into the bottom I mounted the cap board on the front. I ran the DC wires out the top and laced them down so they wouldn't rub against the lid.
While running the amp in on the bench I did do some testing to make sure I wasn't missing anything. Gain came out to 16dB and matched on both channels. THD+N 1watt/8ohms measured around 0.0089% and S/N for that same condition 85dB in one channel and 86dB in the other. That actually probably represents my test setup more than the amp since redressing and moving cables around could change the result by 2 to 4 dB. BW was a surprise with a -3dB point around 520KHz with no ringing on square waves and stable operation so far.
I think it's a credit to the design that so many people in so many ways can build something that performs that well that easily over and over again. You can see from the photos there is nothing exotic about it at all.
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Pass DIY Addict
Joined 2000
Paid Member
Great looking amp and a nice bench as well! Congrats on your new amp!
It's waaaaay too late now, but it would be interesting to know how many amps have been built as a result of this website being around for the last 19 years!
It's waaaaay too late now, but it would be interesting to know how many amps have been built as a result of this website being around for the last 19 years!
to BluesTM #4789
Hello BluesTM,
very nice F5 - build.
Enjoy the music!
I love my F5 playing with my ESLs.
Greets
Dirk
Hello BluesTM,
very nice F5 - build.
Enjoy the music!
I love my F5 playing with my ESLs.
Greets
Dirk
Pass DIY Addict
Joined 2000
Paid Member
With two fans so close to each other, that would cause a "short circuit" in the airflow.
You have to put some baffles in between them.
If there is an intake towards the front or bottom of the case, the original idea should work.
You never want to "circulate" the air in a hot chassis. There has to be a very clear airflow direction - an air 'current' so to speak, air/airflow/heat is almost exactly the same thing as electricity, but in a different medium.
