Frontend for using singled amp in balanced/bridged mode
I have been working on the frontend for driving two TSSA V1.7 in balanced/bridged mode. Actually it can be used on any amp.
The frontend has the same size as the TSSA V1.7 which is 93x63mm and an height of 25mm above the PCB.
The board will cost 84€ so it is a bit expensive but there is value for the money. One could argue why not just use an Lundahl LL1540 transformer!? First of all the LL1540 needs a pcb, secondly the bandwidth of the LL1540 goes to 50KHz (-3dB) where the true balanced driver i will provide will go to at least 500KHz. Distortion will be at least a 10x factor lower.
There is no use of balance line receiver from TI, AD or any other.. it is purely discrete with the right mix of bjt and jfet transistors.
To summarize what the BL frontend will give you.
And the pricetag for this module is 84€/channel.
I have been working on the frontend for driving two TSSA V1.7 in balanced/bridged mode. Actually it can be used on any amp.
The frontend has the same size as the TSSA V1.7 which is 93x63mm and an height of 25mm above the PCB.
The board will cost 84€ so it is a bit expensive but there is value for the money. One could argue why not just use an Lundahl LL1540 transformer!? First of all the LL1540 needs a pcb, secondly the bandwidth of the LL1540 goes to 50KHz (-3dB) where the true balanced driver i will provide will go to at least 500KHz. Distortion will be at least a 10x factor lower.
There is no use of balance line receiver from TI, AD or any other.. it is purely discrete with the right mix of bjt and jfet transistors.
To summarize what the BL frontend will give you.
- operation range from +/-20V to +/-60VDC covering the most amps voltagerange
- linear shunt based voltage regulators for the circuits
- Fully balanced input
- fully discrete solution with jfet and bjt's
- wide bandwidth
- relatively low distortion
- zero global feedback
- input for both RCA and XLR (Differential drive)
And the pricetag for this module is 84€/channel.
It can be biased from 200mA up to 2A.
But to dissipate 140Watt (+/-35VDC and 2A) it will require heatsink of 0.2K/W, thermal grease, firm mounting of the mosfet with the complete surface under tension not just the mounting hole. with an heatsink of 0.2K/W the heatsink will reach 28 degrees above room temperature.
With 1.6A (112Watt per channel) it will reach 40Watt in pure class A into 8R. But for this i would still suggest 0.2K/W heatsink as it would reach 23 degrees above room temperature.
An suggest heatsink is:
SK 435, Standard extruded heatsinks, Heatsinks f.cool, Fischer Elektronik
SK 531, Standard extruded heatsinks, Heatsinks f.cool, Fischer Elektronik
with 0.4A it will be around 3Watt class into 8R. wich can easily be dissipated on SK56 100 mm
But to dissipate 140Watt (+/-35VDC and 2A) it will require heatsink of 0.2K/W, thermal grease, firm mounting of the mosfet with the complete surface under tension not just the mounting hole. with an heatsink of 0.2K/W the heatsink will reach 28 degrees above room temperature.
With 1.6A (112Watt per channel) it will reach 40Watt in pure class A into 8R. But for this i would still suggest 0.2K/W heatsink as it would reach 23 degrees above room temperature.
An suggest heatsink is:
SK 435, Standard extruded heatsinks, Heatsinks f.cool, Fischer Elektronik
SK 531, Standard extruded heatsinks, Heatsinks f.cool, Fischer Elektronik
with 0.4A it will be around 3Watt class into 8R. wich can easily be dissipated on SK56 100 mm
Buy list
Dane 2 x TSSA V1.7
Myint67 2 x BL drive modules, 2 x TSSA V1.7
vgeorge 2 x TSSA V1.7 without mosfets ECW20N/P20-Z + Salas 2 x TSSA V1.7 - Paid
buzzforb 2 x TSSA V1.7 - Paid
pdb 2 x TSSA V1.7 + 2 capkits
Michael G and on of his fellows 6 x TSSA V1.7. (He already has 2 running)
Stajo 2 x BL drive modules, 4 x TSSA V1.7
Prices:
BL drive module: 84€/channel
TSSA V1.7 1 - 3 pcs: 100€/channel
TSSA V1.7 4 - 10 pcs: 90€/channel
CAPBANK BARE PCB costs 13€/board
CAPBANK complete assemblied : 137€/unit
CAPBANK complete unassemblied : 111€/unit
Softstart inclusive iec inlet, fuse drawer, main switch, illuminated power button: 114€/unit
Dane 2 x TSSA V1.7
Myint67 2 x BL drive modules, 2 x TSSA V1.7
vgeorge 2 x TSSA V1.7 without mosfets ECW20N/P20-Z + Salas 2 x TSSA V1.7 - Paid
buzzforb 2 x TSSA V1.7 - Paid
pdb 2 x TSSA V1.7 + 2 capkits
Michael G and on of his fellows 6 x TSSA V1.7. (He already has 2 running)
Stajo 2 x BL drive modules, 4 x TSSA V1.7
Prices:
BL drive module: 84€/channel
TSSA V1.7 1 - 3 pcs: 100€/channel
TSSA V1.7 4 - 10 pcs: 90€/channel
CAPBANK BARE PCB costs 13€/board
CAPBANK complete assemblied : 137€/unit
CAPBANK complete unassemblied : 111€/unit
Softstart inclusive iec inlet, fuse drawer, main switch, illuminated power button: 114€/unit
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I need Dane, Myint67, and Pdb to email me at mail@mirand-audio.dk
This way i can send an proforma invoice, it cannot be done through diyaudio message system.
Payments are done with paypal.
My first thought was no... But i will ship it with the boards together with the schematic. It is very novel, and i don't want to share it with other people who might try to make money on my design.
So if you buy the BL module, you will get the schematic.
- Sonny
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Buy list
Dane 2 x TSSA V1.7
Myint67 2 x BL drive modules, 2 x TSSA V1.7, 1 x softstart
vgeorge 2 x TSSA V1.7 without mosfets ECW20N/P20-Z + Salas 2 x TSSA V1.7 - Paid
buzzforb 2 x TSSA V1.7 - Paid
pdb 2 x TSSA V1.7 + 2 capkits
Michael G and on of his fellows 6 x TSSA V1.7, 1 x softstart. (He already has 2 running)
Stajo 2 x BL drive modules, 4 x TSSA V1.7
Prices:
BL drive module: 84€/channel
TSSA V1.7 1 - 3 pcs: 100€/channel
TSSA V1.7 4 - 10 pcs: 90€/channel
CAPBANK BARE PCB costs 13€/board
CAPBANK complete assemblied : 137€/unit
CAPBANK complete unassemblied : 111€/unit
Softstart inclusive iec inlet, fuse drawer, main switch, illuminated power button: 114€/unit
Dane 2 x TSSA V1.7
Myint67 2 x BL drive modules, 2 x TSSA V1.7, 1 x softstart
vgeorge 2 x TSSA V1.7 without mosfets ECW20N/P20-Z + Salas 2 x TSSA V1.7 - Paid
buzzforb 2 x TSSA V1.7 - Paid
pdb 2 x TSSA V1.7 + 2 capkits
Michael G and on of his fellows 6 x TSSA V1.7, 1 x softstart. (He already has 2 running)
Stajo 2 x BL drive modules, 4 x TSSA V1.7
Prices:
BL drive module: 84€/channel
TSSA V1.7 1 - 3 pcs: 100€/channel
TSSA V1.7 4 - 10 pcs: 90€/channel
CAPBANK BARE PCB costs 13€/board
CAPBANK complete assemblied : 137€/unit
CAPBANK complete unassemblied : 111€/unit
Softstart inclusive iec inlet, fuse drawer, main switch, illuminated power button: 114€/unit
Regarding my softstart module:
Normally the software on the microcontroller on the softstart is configured in such a way that connector J9 is for remote start (That is if you have an preamp with an remote output to enable an power amp).
I can offer a different software for this module which make it possible to use the output DC protection from lazycat to switch off the amp is case of DC on the speaker terminals.
By using J1 and J9 together with an new software it is possible.
By the way. The Softstart modules i ship is black to match the TSSA V1.7 boards.
- Sonny
Normally the software on the microcontroller on the softstart is configured in such a way that connector J9 is for remote start (That is if you have an preamp with an remote output to enable an power amp).
I can offer a different software for this module which make it possible to use the output DC protection from lazycat to switch off the amp is case of DC on the speaker terminals.
By using J1 and J9 together with an new software it is possible.
By the way. The Softstart modules i ship is black to match the TSSA V1.7 boards.
- Sonny
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