F5 Turbo Builders Thread

Aluminum plate on back of heatsinks.
 

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Ah, so I mount the outputs transistors to the plate and mount the plate to the sinks? Why can't I mount the outputs transistors to the sinks directly?

Also newbie question. If the square black things are outputs transistors then what are the round silver things I've seen on earlier SS amp?
 
I just finished the V3 monoblocks, biased everything. Plugged it in and everything sounds fine. Full range and detail for days. I do have a problem however. There seems to be hardly any gain. If i were to guess it would unity gain coming out of the V3s. I read that this should have a gain into the 20dBs in standard config? What am i missing here? I have 98dB efficient speakers and i have my pre-amp (12dB gain).
 
Ah, so I mount the outputs transistors to the plate and mount the plate to the sinks? Why can't I mount the outputs transistors to the sinks directly?

Also newbie question. If the square black things are outputs transistors then what are the round silver things I've seen on earlier SS amp?

you would't be able to evenly distribute the heat over 3 parts of heatsinks without the baseplate as a heat spreder.
the round silver ones you have seen are old type transistors. There's not much of them left.
 
Ah, so I mount the outputs transistors to the plate and mount the plate to the sinks? Why can't I mount the outputs transistors to the sinks directly?

Also newbie question. If the square black things are outputs transistors then what are the round silver things I've seen on earlier SS amp?

Also, since this is a DC coupled SS amp it relies on balance between the P and N transistors or you will get DC on the output. Sounds scary, but it's really not...it's common in SS amps. Temp differences effect this balance. So you want the transistors to be the same temp...thus the baseplate to spread the heat.

The transistor shape is just the "case". The silver metal round cases are designed for mounting on an "L" shaped piece with a hole in them and are definitely not as popular these days.
 
I just finished the V3 monoblocks, biased everything. Plugged it in and everything sounds fine. Full range and detail for days. I do have a problem however. There seems to be hardly any gain. If i were to guess it would unity gain coming out of the V3s. I read that this should have a gain into the 20dBs in standard config? What am i missing here? I have 98dB efficient speakers and i have my pre-amp (12dB gain).

With speakers disconnected feed the f5 test tone at a known voltage...say 1V. See what comes out of the speaker binding posts for volts. Then you will know.

A mistake in the feedback network (resistor values) would explain lack of gain and the amp still working.
 
Here is the plan. The 12"x12" pyramid will house the power supply and on the side of the pyramid the 45 degree pipe sockets will attach to boxes that are 7"w x7"d x15" tall with the heat sinks on the front. These boxes will stand straight up so the airflow will go up through them.

What issues do you see will this design???
 

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Here is the plan. The 12"x12" pyramid will house the power supply and on the side of the pyramid the 45 degree pipe sockets will attach to boxes that are 7"w x7"d x15" tall with the heat sinks on the front. These boxes will stand straight up so the airflow will go up through them.

What issues do you see will this design???

I think that's a lot of weight for some fairly thin aluminum. The transformer is pretty heavy and the heatsinks will be heavy as well.
 
Also, another thing i found in the process of building the V3 monoblocks. I am using 4 amp fuses in the power switch that at comes with the back panel kit. If i use the switch with straight mains power i blow a fuse every time. The only way i can start them is with my variac, slowly. I don’t know if i have under fused it or if i just need to use the soft start. I have ordered the soft start kit to be safe.