You have a case with a 160VA transformer.
Here is my suggestion. Get a stereo kit, one power supply board and two amp boards. That will get you started and make sound for the least amount of investment. So now you have this stereo amp and you built it yourself and things are looking good. Purchase a mono kit, one power supply and one amp board. Build it and you have 3 channels now, cool!! If you are still into this stuff ( you prolly will be a bit addicted by now) get two more mono kits, that would give you front L,R, and Center mono amps and you can use the stereo amp and power supply you first built for the rear channels. Congrats you now have a 5 channel amp! Sweet!!
Here is my suggestion. Get a stereo kit, one power supply board and two amp boards. That will get you started and make sound for the least amount of investment. So now you have this stereo amp and you built it yourself and things are looking good. Purchase a mono kit, one power supply and one amp board. Build it and you have 3 channels now, cool!! If you are still into this stuff ( you prolly will be a bit addicted by now) get two more mono kits, that would give you front L,R, and Center mono amps and you can use the stereo amp and power supply you first built for the rear channels. Congrats you now have a 5 channel amp! Sweet!!
The local retail price for 160VA trafos is $80 AU.$240 for 3pc 100VA transformers???? inkl shipping from another planet?
$18 a pc at antek
80VA (next standard size) is hardly less. To build a dual mono design with separate rail supplies and also have reasonable bass with scope for paralleling or bridge tying chips (likely) will require 3 trafos because the present transformer is only 2 x15VAC. Unfortunately, import costs for heavy items here is now absurdly expensive for Oz residents, particularly from UK and US origins. The representatives of Farnell and RS here do also import their ranges of Chinese trafos, but via the UK!!
Yes, I probably would, but for safety issues with my younger friends, whom I supply with these hard-to-get bits.holy ****. i would do smps PSU's in the future if i were you
Okay so to confirm with everyone once more before i send off my money (a single tear rolls down my face), at this stage, I should be buying:
a stereo kit 70
a single mono kit 50
Postage 36
And a toriodal supply, I am looking at a 100VA 2x22V one linked below for AUD$67 + Postage, is this a good option?
RK120/22 - BLOCK - TRANSFORMER, 120VA, 2 X 22V | element14 Australia
Have i missed anything?
EDIT: And I am guessing that the ebay transformers aren't suitable? Because if they are they are much cheaper!
a stereo kit 70
a single mono kit 50
Postage 36
And a toriodal supply, I am looking at a 100VA 2x22V one linked below for AUD$67 + Postage, is this a good option?
RK120/22 - BLOCK - TRANSFORMER, 120VA, 2 X 22V | element14 Australia
Have i missed anything?
EDIT: And I am guessing that the ebay transformers aren't suitable? Because if they are they are much cheaper!
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From your other eye, squeeze another tear or 3 because you'll need a second transformer to drive the centre (bass?) channel. The amplifiers produce about 40W/8R, 60W/4R so your 100 or 120VA transformer will be at the max, should you ever dial up full power from your stereo pair.
Amplifiers are not 100% efficient so an 8 ohm output rating of 40W implies an input of ~ 60W power is required for each channel and that snaps up all your max. power rating with both channels. True, music seldom occupies the full power range avalable, but lower impedance loads (more power output) and extra channels (1.5 * stereo load) soon will. If the third channel is for bass, it's likely better not to have the current demand for that sucking the supply down and modulating the sound from the front channels. A small, 120VA trafo will work fine in stereo at moderate levels but don't try to do it all without accepting some harsh limitations. Get a separate suppy for the other channel but use the same transformer type so it can double for the other channel when you go full bore with the double mono version (sometime).
Amplifiers are not 100% efficient so an 8 ohm output rating of 40W implies an input of ~ 60W power is required for each channel and that snaps up all your max. power rating with both channels. True, music seldom occupies the full power range avalable, but lower impedance loads (more power output) and extra channels (1.5 * stereo load) soon will. If the third channel is for bass, it's likely better not to have the current demand for that sucking the supply down and modulating the sound from the front channels. A small, 120VA trafo will work fine in stereo at moderate levels but don't try to do it all without accepting some harsh limitations. Get a separate suppy for the other channel but use the same transformer type so it can double for the other channel when you go full bore with the double mono version (sometime).
Wait up, the 160VA trafo only has 15VAC windings. That results in ~ +/- 21V DC supply. It will work, but power will be limited to around half the ratings. If that's OK, fine; use that supply for both channels and use your 22V windings transformer for the centre, bass, whatever. At this low power, you could probably run all 3 channels from 1 power supply, though much smaller LM1875 chipamps can cover that requirement OK.
Have you read section eleven in the assembly manual? That should give some idea of what's considered suitable.
As far as Ebay is concerned, you are dealing with unknown Chinese product from there and German product from E14. If cheapest, uncertified quality is fine, then buy what you will and hope for the best.
Have you read section eleven in the assembly manual? That should give some idea of what's considered suitable.
As far as Ebay is concerned, you are dealing with unknown Chinese product from there and German product from E14. If cheapest, uncertified quality is fine, then buy what you will and hope for the best.
I did not even see the manual on the chipamp site, it is very good!
I realize now that the transformer I have really is going to let me down, and i would rather do it right the first time. Maybe i should just leave the 160VA transformer for another project and buy new ones? If this is the case should i go for 3 mono channels?
Cya later pay checks haha
I realize now that the transformer I have really is going to let me down, and i would rather do it right the first time. Maybe i should just leave the 160VA transformer for another project and buy new ones? If this is the case should i go for 3 mono channels?
Cya later pay checks haha
Also see manual linked from post #34
I think it's wise for the long term, to drop the current trafo. I would use 2 transformers the same as explained, which will cost more but still good if you take the Ebay option and the choice of 22-25 VAC windings @120VA at an attractive price. (check the freight rate carefully) That's 3kg+ to airfreight and not cheap any more, even from Hong Kong.
I think it's wise for the long term, to drop the current trafo. I would use 2 transformers the same as explained, which will cost more but still good if you take the Ebay option and the choice of 22-25 VAC windings @120VA at an attractive price. (check the freight rate carefully) That's 3kg+ to airfreight and not cheap any more, even from Hong Kong.
No two anything will be the same unless made by an identical process from same materials. Used well within ratings though, you could expect quite similar performance so at low levels, as in most of the time in domestic situations, where the supply voltages are sufficient to prevent much clipping, there will be little difference in the audio that could be attributed to using different source transformers.
In any case, if you use 1 transformer for both stereo channels, there's nothing to compare. If the centre channel is then powered differently, there should still be no issues. Buy 2 now and have matched dual mono with same trafos in the future, making certain you have all the bases covered..
In any case, if you use 1 transformer for both stereo channels, there's nothing to compare. If the centre channel is then powered differently, there should still be no issues. Buy 2 now and have matched dual mono with same trafos in the future, making certain you have all the bases covered..
you can get 1pc 160-225VA 2*22V for the stereo set(1pc PSU and 2ch amp). and 1pc 100VA 2*22V for the center ch.
or. 2pc 100VA 2*22V for dual mono set(2pc PSU and 2ch amp). and 1pc 100VA 2*22V for the center ch.
or. if you plan on doing a 5ch. you can get 1pc 400-500VA 2*22V and 1pc PSU with 60.000uF cap bank. f.ex aleph PSU board that chipamp have.
that will save you some money total.
i'am actualy doing this right now
or. 2pc 100VA 2*22V for dual mono set(2pc PSU and 2ch amp). and 1pc 100VA 2*22V for the center ch.
or. if you plan on doing a 5ch. you can get 1pc 400-500VA 2*22V and 1pc PSU with 60.000uF cap bank. f.ex aleph PSU board that chipamp have.
that will save you some money total.
i'am actualy doing this right now
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Sure, if doesn't start you crying and you want to go the whole dual-mono way.
Nope, but you can copy the Ebay item number into the post as a reference and that can be pasted into browsers for a similar result. Just check you've captured the complete number before postingcjflis said:
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