The electrical contact between a push-on terminal (faston) and the tab is rather good. They fit very tightly and thus scrape off any oxide layer when making contact. Next comes the connection of the wire to the push-on part. Properly crimped connections are better than soldered. If you do not have a real crimping tool to attach the push-on terminals to the wires, you may elect to solder the wires straight to the faston tabs.
The coupling capacitors are marked C7/C8, and can be recognised because they're mounted to the left and right of the op amp.
The coupling capacitors are marked C7/C8, and can be recognised because they're mounted to the left and right of the op amp.
A little bit off-topic but,
I need to find a good address in the Netherlands or Belgium for electronics components.
I've found a few companies here in Antwerp, but they are all very unsupportive and order everything straight from Velleman.
This means I'm unable to find 800VA toroidal transformers with 2*42V secondaries. Only 38 and 45.
Any tips for nice HiFi sized casings (+/-43cm wide) would be welcome as well!
Just ordered the HQ PSU from Hypex, now all I need is a good transformer and softstart!
I need to find a good address in the Netherlands or Belgium for electronics components.
I've found a few companies here in Antwerp, but they are all very unsupportive and order everything straight from Velleman.
This means I'm unable to find 800VA toroidal transformers with 2*42V secondaries. Only 38 and 45.
Any tips for nice HiFi sized casings (+/-43cm wide) would be welcome as well!
Just ordered the HQ PSU from Hypex, now all I need is a good transformer and softstart!
Obviously, I don't know of anyone in The Netherlands or Belgium, but have you tried Plitron in Toronto, Canada?
They don't have 800VA transformers either, but they can custom build it (might be kind of expensive) or you can purchase their standard 1000VA transformer with output voltage options of 40 V or 45 V. Do you prefer 42 V secondaries because 45 V is too close to the max operating condition for V+/V-?
45 V RMS * 1.414 = 63.63 V peak.
Subtract a volt or so (not sure how much is used here) for the diodes and capacitor discharge and that's what I might expect as a DC output voltage. So a 45 V secondary will give you a peak voltage output of up to 62.6 V. This is very close to max rating of 63 V. However, I've read where the amount of loss from diodes and capacitor discharge can be as high as 4 V.
If you go with 42V, it gives you a peak voltage output of up to 58.38 V. Which is well within the maximum operating condition...
They don't have 800VA transformers either, but they can custom build it (might be kind of expensive) or you can purchase their standard 1000VA transformer with output voltage options of 40 V or 45 V. Do you prefer 42 V secondaries because 45 V is too close to the max operating condition for V+/V-?
45 V RMS * 1.414 = 63.63 V peak.
Subtract a volt or so (not sure how much is used here) for the diodes and capacitor discharge and that's what I might expect as a DC output voltage. So a 45 V secondary will give you a peak voltage output of up to 62.6 V. This is very close to max rating of 63 V. However, I've read where the amount of loss from diodes and capacitor discharge can be as high as 4 V.
If you go with 42V, it gives you a peak voltage output of up to 58.38 V. Which is well within the maximum operating condition...
I always read here that 45 secondaries are too high for UcD400, or was the cleared in the new versions?
I'm going to use the HQ power supply by Hypex to run 2 of them. The caps on that PS are 63V, so that's also a worry at 45V.
If I have a 10% overshoot on the mains voltage (which is not impossible in Belgium) I hit 69V on the rails, wouldn't that trigger the over voltage?
Thanks for your opinion!
I'm going to use the HQ power supply by Hypex to run 2 of them. The caps on that PS are 63V, so that's also a worry at 45V.
If I have a 10% overshoot on the mains voltage (which is not impossible in Belgium) I hit 69V on the rails, wouldn't that trigger the over voltage?
Thanks for your opinion!
Jan-Peter,
Thanks for the suggestion. 2x500VA and 2 HQ PS are simply too expensive for my budget.
The reason I'm looking at 800VA is partly psychological, I must admit.... I will be using the amps nowhere near their max output in normal life (stereo channels of a surround setup, about 70% stereo, 30% surround) so i'm not worried there, even when my speakers are known to be very current hungry ("old" B&W nautilus 804)
However sometimes we do have a "fuif" (party) sometimes, and I want to use my amp there as well. Usually we connect 4 speakers so we hit 4 ohms (and probably lower) pretty often at high volumes. I'm not sure if 500VA + 1 HQ PS will handle your typical heavily compressed techno music at sustained high volume? I'd love to have a software tool to check out what the average percentage of maximum output power for a giving recording is.
Would it however, be possible to connect 2 of your 500VA's to a single power supply or is this totally not recommended/impossible?
All suggestions are welcome. I want to get rid of my "test setup" that's been running for way too long. It looks like sh..
You can play a party with 2 UcD400's on one 500VA transformer and one supply with absolutely no problems. This is really no problem. The last time I measured average power in heavily compressed music, it was still below 10% of constant sinewave of equal amplitude.
Only if you are making amplifiers for export to South America, using a larger transformer can be worthwhile because it is a known fact that parties are played in full clip there, and last for days (only half joking there).
Only if you are making amplifiers for export to South America, using a larger transformer can be worthwhile because it is a known fact that parties are played in full clip there, and last for days (only half joking there).
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