I tried that, but it never worked the first time. I just tried it again and got more options. Thanks!
Thanks pthep!
Yeah 🙂 , I'm trying to figure out what people have done with the Soft Start / DC protect / speaker connect
I'm sure the DIY audio store softstart will be fine. I copied that design for all six amps I run now. Each has a 600 or 800 va transformer. 72 to 85 volt rails.
I have not used their speaker protection.
I have not used their speaker protection.
This design is working great and covers all protection needs. http://www.diyaudio.com/forums/soli...-st-century-protection-board.html#post4110406
That's pretty neat. Would you be able to give a rough cost estimate on the build?
I guess I could save my DIY boards for a future project if I go with this set-up.
It's not a cheap system to build mainly because of the mosfets and Opto in the speaker relays. I've never added up parts cost but it's likely around $120CDN to build a stereo system.
Well, I am almost 40% over budget so far. Might as well round it up to 50% 😛 . In all honestly, I am completely overwhelmed with all the options.
I started out building a set of speakers. Now I am building A set of speakers, Amp, Protection, and most likely a pre-amp/ DAC.
It's a good thing money grows on trees... 😀
EDIT in Bold. Did some Newfie math!
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The first build is the hardest. Everyone hates having so many options. Once you get the first one running, you figure out how easy it is to mix and match parts.
I always think the protection system is money well spent. It's hard to hurt an amplifier once the protection is installed and it's cheaper than a good set of speakers.
I always think the protection system is money well spent. It's hard to hurt an amplifier once the protection is installed and it's cheaper than a good set of speakers.
Agree 100%. I'd prefer to buy my speakers only once!
Speaking of protection 🙂 ; I was peeking at the spec sheet for the K1/K2 Speaker protection relays used in the 21st design. I'm a little bit confused at the ratings because the problem I was having with the DIY Audio boards was that the relay could not safely handle the 63V rails I was using. This relay doesn't seem to be rated much higher. Am I missing something?
Skip to the end of the thread. It's evolved quite a bit.It's now a modular design and uses mosfets instead of mechanical relays.
Thanks. This is very interesting! I will have to take my time and read through as much as possible in that thread.
It looks as though I should be able to order my Badger BOM equipment, and still have enough stuff to buy to qualify for free shipping on a second order once I figure out the Protection/ PSU boards. This would let me start assembling the Badgers when I return home from work next month!
Anyone,
When looking at resistor temp efficiency, is a lower +/- PPM/C better? (+/-100PPM VS +/- 300PPM VS -10/-100PPM) ?
When looking at resistor temp efficiency, is a lower +/- PPM/C better? (+/-100PPM VS +/- 300PPM VS -10/-100PPM) ?
It will be higher.
a 230:40-0-40Vac gives me +-58.5Vdc, when mains is at 240Vac
I would expect +-65Vdc for a 115:45-0-45 when mains is at 115 and a bit higher when mains is high.
That would allow a maximum output of around 50Vpk to 60Vpk driving an 8r0 test load.
50Vpk = 156W into 8r0
60Vpk = 225W into 8r0
Using my standard guide for output device power requirement.
max Power times 5, for BJTs, indicates that 780W to 1125W of device Pmax.
A 3pr output stage will work with 6 off 130W to 190W devices.
There are lot's of plastic package BJTs in the range 130W to 230W.
Choose any that have good SOA ~ 65Vce (that does NOT include 2sa1943/c5200 !!!!!).