TSSA - The Simplest Symmetrical Amplifier - Page 58

Lazy Cat · 12th May 2012, 11:20 PM

Quote:

Originally Posted by sonnya

Hi all.

The Capbank is finished it fits all CAN style caps with an terminal pitch of 28.5mm

BHC Aerovox
Kemet
RIFA PEH200
..

A nice suggestion would be:

peh200ko6100mu2

100000uF 40V.

http://sitosite.dk/amps/rifa-capbank.pdf

It uses blade terminals so we can fit AWG12 cables on it.

It uses an external bridge rectifier like GBPC3502 (Place an RC filter across the output of it).

I see very serious approach here

2 x 0,1 F/40 V is expected overkill from you Sonnya.

sonnya · 13th May 2012, 07:37 AM

What i like about them is the low ESR at 10khz of < 15mOhm....

Idefixes · 13th May 2012, 05:12 PM

Hi all,

I finally find the time this afternoon to etch TSSA BIGBT HP, need yet to drill

Lazy Cat · 13th May 2012, 09:15 PM

Quote:

Originally Posted by Idefixes

Hi all,

I finally find the time this afternoon to etch TSSA BIGBT HP, need yet to drill

Hi Marc

PCB-s are looking great, we're just about to start soldering separate stages and simultaneously testing their functionality. It will be systematic construction process, also very educational one and above all a lot of fun.

Regards Andrej

Idefixes · 13th May 2012, 09:48 PM

Quote:

Originally Posted by Lazy Cat

Hi Marc

PCB-s are looking great, we're just about to start soldering separate stages and simultaneously testing their functionality. It will be systematic construction process, also very educational one and above all a lot of fun.

Regards Andrej

Yes but first have to drill, to mesure BC550/560 and 2SA/2SA (no idee for conditions to achiev mesure for these)....

Marc

Lazy Cat · 14th May 2012, 07:17 AM

Quote:

Originally Posted by Idefixes

Yes but first have to drill, to mesure BC550/560 and 2SA/2SA (no idee for conditions to achiev mesure for these)....

Marc

Regular hFE measurement by multimeter with this function is completely sufficient. Multimeters measure hFE at Ic=1 mA and that is OK for relative matching. Several times I rechecked hFE matching by Ic=100-500 mA by other methods and matched transistors always stayed in the same pairs as defined by multimeter. You are not seeking absolute hFE value of each BJT but using only relative comparison to find best matches.

Idefixes · 14th May 2012, 08:09 AM

Quote:

Originally Posted by Lazy Cat

Regular hFE measurement by multimeter with this function is completely sufficient. Multimeters measure hFE at Ic=1 mA and that is OK for relative matching. Several times I rechecked hFE matching by Ic=100-500 mA by other methods and matched transistors always stayed in the same pairs as defined by multimeter. You are not seeking absolute hFE value of each BJT but using only relative comparison to find best matches.

So i must be able to use the schematic below for this use. 0R22 are arrived to...

Marc

Lazy Cat · 14th May 2012, 09:11 AM

Quote:

Originally Posted by Idefixes

So i must be able to use the schematic below for this use. 0R22 are arrived to...

Marc

What's the purpose of this sch? BJT matching I suppose, but why not using hFE function of multimeter? You don't have multimeter with hFE function?

Idefixes · 14th May 2012, 09:16 AM

Yes BJT matching. My Fluke don't have Hfe fonction. I have another with Hfe function but the DMM is really cheap and basic one. Don't know if i can trust in it. Must check if the Hfe socket is useble for To126 package.

Marc

AndrewT · 14th May 2012, 09:53 AM

The hFE function on most cheap and cheaper DMM is based on a constant Ib. This gives misleading results.
But worse, the Ib is set so low that, the hFE results are for an Ic that is off the left side of most manufacturers' plots of hFE vs Ie.

This combination of design faults makes the added on hFE function a virtual waste of effort and waste of resources.

14th May 2012, 09:16 AM	#579
Idefixes diyAudio Member Join Date: Dec 2003 Location: Mulhouse - Alsace	Yes BJT matching. My Fluke don't have Hfe fonction. I have another with Hfe function but the DMM is really cheap and basic one. Don't know if i can trust in it. Must check if the Hfe socket is useble for To126 package. Marc __________________ website : http://audiyofield.wifeo.com/index.php

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13th May 2012, 07:37 AM	#572
sonnya diyAudio Member Join Date: Oct 2001 Location: Denmark	What i like about them is the low ESR at 10khz of < 15mOhm....

14th May 2012, 09:53 AM	#580
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	The hFE function on most cheap and cheaper DMM is based on a constant Ib. This gives misleading results. But worse, the Ib is set so low that, the hFE results are for an Ic that is off the left side of most manufacturers' plots of hFE vs Ie. This combination of design faults makes the added on hFE function a virtual waste of effort and waste of resources.