Same SMPS generic, never tested but yes, very much possible the same sound character although with unlimited power. 😎
Theatsink=Troom + 35,28 W * 0,67°K/W=23°C + 23,64°C=46,64°C (idle)
Quite high heatsink temperature in idle state, I would suggest to use 0,5°K/W or even less. 😎
Important notice to GB members
Hi all dear
Guys don't be fooled with a small size of the First One modules possibly holding in your hands just now, got to know this: this is a very BIG amplifier considering sound signature, be prepared to be strongly surprised immediately after turning this little beast alive.
At the moment, all GB members already received the modules, please slowly prepare all the mechanics, chassis, heatsinks, terminal connectors, etc., but please don't do any wiring yet. On daily basis testing of the First One in the chassis is taking place, the aim is to find out the best possible grounding scheme and I can tell you all that we already have it. Final touch in day or two and then new detailed chassis wiring scheme will be published in this thread or maybe just sending it to PM of GM members, we'll see.
Regards, L.C.
Hi all dear
Guys don't be fooled with a small size of the First One modules possibly holding in your hands just now, got to know this: this is a very BIG amplifier considering sound signature, be prepared to be strongly surprised immediately after turning this little beast alive.
At the moment, all GB members already received the modules, please slowly prepare all the mechanics, chassis, heatsinks, terminal connectors, etc., but please don't do any wiring yet. On daily basis testing of the First One in the chassis is taking place, the aim is to find out the best possible grounding scheme and I can tell you all that we already have it. Final touch in day or two and then new detailed chassis wiring scheme will be published in this thread or maybe just sending it to PM of GM members, we'll see.
Regards, L.C.
Attachments
Hi LC,
it really sounds good. I really enjoy this project.
Please excuse my stupid question, but on page 1, it is written:
"Maximal power (20 Hz - 20 kHz, THD 0,1 %)
160 Wrms/8 Ohm
250 Wrms/4 Ohm"
So why a SMPS1200 is needed ?
Regards,
Christian.
it really sounds good. I really enjoy this project.
Please excuse my stupid question, but on page 1, it is written:
"Maximal power (20 Hz - 20 kHz, THD 0,1 %)
160 Wrms/8 Ohm
250 Wrms/4 Ohm"
So why a SMPS1200 is needed ?
Regards,
Christian.
LC the Mundorfs onboard are rated at 63 volt.
The Hypex SMPS output 64 volt.
Is it safe ?
The Hypex SMPS output 64 volt.
Is it safe ?
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Mundorf max. short term voltage rating is 72V. Since Hypex smps are not regulated, their output voltage sag under the load. With 230V mains voltage, you get around 59-60V.
Because of its output current capability, speaker's impedance can easily go as low as 2 Ohm anywhere in impedance curve, so if we calculate current needed ...
Because of its output current capability, speaker's impedance can easily go as low as 2 Ohm anywhere in impedance curve, so if we calculate current needed ...
Thanks LC, I understand. Currently I have for a L15D a SMPS500, do you think it can be enough to power 2 channels first one?
Yes, it is stable even at lower impedance. But do not confuse stability with current capability, it is limited by SOAR and Imax of power transistors.
Martin Logan electrostatic loudspeakers are notoriously known as to have low impedance at 20 kHz, less than 1 Ohm of capacitive character, no problem for the First One. 😉
Actually,
I don't Have the specs of my speakers : my brother built them. They are 2 ways speakers, 8ohm, 89db.
For the SMPS, it is a Connexelectronic 500R. I use it for my L15D:
SMPS500R +-55V (dual voltage) 230V Power Supply
Is this helpful: (If i have misunderstood the subject someone please pop in and correct)
low impedance load needs current elastic.
High impedance load needs voltage elastic.
Example SMPS500R. Current x Voltage = watts (7,8125 x 64 = 500), therefor buing SMPS in same wattage envelope rule = high voltage 64V you get less current (optimal for high impedance load), and buing lower voltage type one gets more current (optimal for low impedance load).
LC's recommended PSU cover i guess both low/high (4ohm/8ohm) impedance loads by being a 1200watt supply.
Therefore if on a budget and you go SMPS500R way, for 8ohm use 64V type and 4ohm 40-50V (last is a guess without investigate further).
For having enough PSU fuel for the amp module not degrading sound performance if using SMPS500R i think you need one SMPS per amp, but of course you can start with your SMPS +/-55V feeding both amps but be aware from some volume and up you degrade the amps sound performance because PSU can't deliver fuel, also because your load seems 8ohm optimal is 64V supply.
Seems a compromise though going SMPS500R way and covering wide impedance load spectra and high volume, but if one never goes highest volume and never replace speakers with other loads, the optimal voltage/current SMPS500R could be used for lover cost.
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Speaker's impedance is likely to be more than 4 ohm anywhere on the curve. 🙂
As SMPS500R is softly switched it has less efficiency, more idle dissipation when connected to the First One, so I definitely recommend you to use one per channel, dual mono configuration for sure. 😉
Thanks BYRTT for your support helping GB members with thorough and very useful advices.
Guys, I have a lot of positive experiences with SMPS1200A400 in over a year period of testing, long term loud listening exhibition sessions, different private systems, customers etc., not even one remark whatsoever raised up till now. As BYRTT already said I picked it because it is universal, providing high power, high voltage and high current, so it covers most types of system configurations, delivering clean power instantly, current on demand always there when needed and best of all in a coolish possible behaviour as cool can be. 😎
Hi LC, I would have a question regarding the recommended Mica insulator to be ordered:
A 25x20mm for TO-247 I suppose : correct?
It seems these are not stocked by the main distributors but are pretty easy to find on ebay though they come on different thicknesses (0.1, 0.2 or 0.25mm). I guess thinner is better for thermal conductivity. Any concern with using 0.1mm thickness?
A 25x20mm for TO-247 I suppose : correct?
It seems these are not stocked by the main distributors but are pretty easy to find on ebay though they come on different thicknesses (0.1, 0.2 or 0.25mm). I guess thinner is better for thermal conductivity. Any concern with using 0.1mm thickness?