F5 Turbo Circuit Boards

[AudioSan]

that is a very high bias/low rail voltage v3. are you running low impedance speakers?

 

[coolnose]

that is a very high bias/low rail voltage v3. are you running low impedance speakers?

given for 8 Ohms, but having some heavy dips, I have an impendance curve somewhere...

I read the multiple power calculation in this thread...as everybody I'd like to stay class A as long as possible... but I need to re-read that calculations again

 

[coolnose]

Impedence plot

Any opinions ?

 

[coolnose]

I assure you the PCB's won't be close to the most expensive parts. By the time you build the power supply and get enough heatsinking!

We've decided to release the rest of the boards right away, which means about a week for them to be in stock...

That should be this week then...

 

[AndrewT]

post2103:
is that 70degrees of phase angle at 4ohms @ ~40Hz
& ~45degrees @ 3ohms @ ~60Hz?

Those will be very demanding of the output stage and drivers with short term loads.
At 40 to 70Hz the tones could be quite sustained. Could high levels of these bass tones these blow up the output stage?

 

[coolnose]

post2103:
is that 70degrees of phase angle at 4ohms @ ~40Hz
& ~45degrees @ 3ohms @ ~60Hz?

Those will be very demanding of the output stage and drivers with short term loads.
At 40 to 70Hz the tones could be quite sustained. Could high levels of these bass tones these blow up the output stage?

Yes Andrew, that's the way to read the graph!

Hence ,my question: As much Power into 4 ohms as possible (higher rails) or as much "class A" as I can get from lower rails ?

 

[AndrewT]

Examine the reactive load temperature de-rated SOAR for the loadings your impedance plot is showing.
Clue:
use Bensen's, or other, SOAR calculations.

 

[coolnose]

Andrew,

I am totally willing to have a closer look, your indications don't help me though.

Could you tell me what you mean by SOAR - I am pretty sure not a jordan village or cognitive architecture.

If it's "Safe Operating Area" then I would just need a hint on where to find information on Bensen.

Thanks,

Max

 

[AndrewT]

He's in the Threads
I have posted many times offering a modified version of Bensen's spreadsheet that can be applied to FETs and BJTs and other changes.
Bensen's work is based on David Eather's paper. That is referenced in the spreadsheet.

 

[coolnose]

Andrew,

if the spreadsheet you are referring to is something like project1.xls and all I have to do is enter my device data, my rail voltage and my capacitance for the power supply, then I think I'am safe for 8 and 4 ohms...

See attached pdf.

 

[AndrewT]

That looks familiar.
It is Bensen's original sheet.

 

[Daniel(Del)]

Hi all!
I'm interested in some of Tea-Bag's boards, however he has currently run out of them.
So if you also want some, please show interest here, so that he can produce a new batch: https://docs.google.com/spreadsheet/ccc?key=0AnAnd3RI56NmdGk2aHZ0dkVGRnc1ZzdrWm9lYzgtOVE

Thank you very much
Daniel

 

[rubofdagreen]

I have a pair I would be willing to sell. I cannot use them, account of my dumpster reclaimed heat sinks, (needed the modular ones from the store). Whatever he charged me plus shipping.

 

[Variac]

Usual Excuses: Family Issues, Day Job, other PCB/chassis issues...
BUT the circuit board sets are now individually labeled, packed and SENT by UPS to the order fulfillment center. Should get there in 2 days plus 2-3 days processing on their end and they'll be in the store. The fulfillment people are more reliable then I as it IS their "Day Job"

 

[coolnose]

F5T boards in stock in the Diyaudio store as per NOW!

Hi,

just a quick note to let everybody know that F5t board are now in stock - US warehouse only though!

Store notification mail does not seem to work, at least not for me.

I have placed my order....

Cheers,

Max

 

[Variac]

Yes they are in stock at last! And they will only be in the USA store for now. The VAT thing is tricky for us and our store..

 

[a.wayne]

Variac ,

What happened to the 8 output pr model, Are we able to use the current 5 pc setup and add the additional outputs ..?


Regards ..

 

[Variac]

You have to get 2 sets.

http://www.diyaudio.com/forums/pass-labs/206756-f5-turbo-circuit-boards-209.html#post3469771

 

[a.wayne]

You have to get 2 sets.

http://www.diyaudio.com/forums/pass-labs/206756-f5-turbo-circuit-boards-209.html#post3469771

Thanks ....

output circuit board dimensions ...?

Any opinions ?

Yes ...

post2103:
is that 70degrees of phase angle at 4ohms @ ~40Hz
& ~45degrees @ 3ohms @ ~60Hz?

Those will be very demanding of the output stage and drivers with short term loads.
At 40 to 70Hz the tones could be quite sustained. Could high levels of these bass tones these blow up the output stage?

Not if he runs enuff and keep them within SOAR....

Yes Andrew, that's the way to read the graph!

Hence ,my question: As much Power into 4 ohms as possible (higher rails) or as much "class A" as I can get from lower rails ?

Your amp will have to be able to sink power continuously into 2 ohm to not have bass issues when driving that load, noticed you have the port tuning at a low 20hz, what size driver ... ?

 

[coolnose]

Thanks ....

output circuit board dimensions ...?





Yes ...



Not if he runs enuff and keep them within SOAR....




Your amp will have to be able to sink power continuously into 2 ohm to not have bass issues when driving that load, noticed you have the port tuning at a low 20hz, what size driver ... ?

Wayne,

quoting you " if he runs enough ****" , I guess you wanted to write bias "bias" ?

Driver is 15"

Cheers,

Max