T-Amp + FE207E + BSC Question

[skrstic]

I’m finishing full range build of MJK Project 5 - http://www.quarter-wave.com/Project05/Project05.html -.
T-Amp - BSC -- Question : Is T-Amp low DF amp and should I go acordinaly to BSC spec http://www.quarter-wave.com/Project05/BSC_Circuit.pdf with 2ohm+0.6mH and up ?


2 Ohm 10W Resistor – Question : 5W or 7W or 10W or 20W or..?
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=016-2

 

[OzMikeH]

damping factor of the Trends T-amps is not low. it's relatively high but not very high. sorry I cant be exact, I havent measured it..

with chosing the resistor size, you need to estimate how much power it will be dissipating. if it was an 8 ohm resistor in series with an 8 ohm driver then it cant be more than 10W for the resistor if driven with a typical t-amp.

 

[skrstic]

thanks

But see this
http://www.41hz.com/Forums/topic.asp?TOPIC_ID=1056
or
http://www.enjoythemusic.com/magazine/viewpoint/0705/nearfield7.htm
or
http://www.diyaudio.com/forums/showthread.php?threadid=71345
300-400???

or http://www.diyaudio.com/forums/showthread.php?threadid=86368

so what ia DF (damping factor ) for t-amp?? HLEES

 

[Lostcause]

Hi skrstic,
I have played with several versions of this BSC with FE207E's + T-amps (various), and in the end....
No BSC and they are jammed in the corner of the room
In fact I've added FT17H's to the back of them to help the top-end 'air'.
Not shouty at all after 300+ hrs. and they go very low.
I only have light wadding in the top half of the cabinets as well.

 

[Scottmoose]

so what ia DF for t-amp??

It depends on the amp.

 

[skrstic]

Original Sonic Impact T-Amp cap mod (http://www.michael.mardis.com/sonic/start.html) not gen2

 

[OzMikeH]

I expect all TA2024 based amps will be fairly similar. there is really only one way to configure the output filter. The series inductors will make some difference.

I asked the same question a while ago elsewhere.
I was told:


"Put an 8R resistor on the output, put out around 1 Watt, measure voltage precisely. Change resistor for 33R and measure again. The second reading will be higher.

Then calculate the currents through the two resistors. Calculate Z out via Ohms law as delta V divided by Delta I."


I sugggest you download a 1kHz wav file and use that.
If you don't know what he is talking about you can find out with google.

Now that gave you the output impedance.
Damping factor is Speaker impedance (at that frequency, see the impedance plot) divided by the amp's outout impedance (which doesn't vary much with frequency in a good amp)