I've just ordered a BrianGT kit and was wondering about some choices regarding a transformer and a pot.
Transformer choices are these.
18V-0-18V 160VA Toroidal Transformer - AU$48
25V-0-25V 160VA Toroidal Transformer - AU$48
18V-0-18V 300VA Toroidal Transformer - AU$69.95
That what Jaycar has that would be suitable (I think).
I was wondering which would be the better of the 3, also counting in the price difference between the 160VA and 300VA? Also, is there a better of cheaper place in Australia to buy/order a transformer?
As for a pot for volume control, i'm not exactally sure what I need for it. Is one of these link the right thing? It's cheap, maybe there is something that will do the job better?
This is my first time with something like this, so all the help I can get would be greatly appreciated!
Transformer choices are these.
18V-0-18V 160VA Toroidal Transformer - AU$48
25V-0-25V 160VA Toroidal Transformer - AU$48
18V-0-18V 300VA Toroidal Transformer - AU$69.95
That what Jaycar has that would be suitable (I think).
I was wondering which would be the better of the 3, also counting in the price difference between the 160VA and 300VA? Also, is there a better of cheaper place in Australia to buy/order a transformer?
As for a pot for volume control, i'm not exactally sure what I need for it. Is one of these link the right thing? It's cheap, maybe there is something that will do the job better?
This is my first time with something like this, so all the help I can get would be greatly appreciated!
It does - if you need maximum power. But remember that many "8 ohm" speakers aren't really 8 ohm - but closer to 6 (or even 4).parrymike said:
So I think 22V is a good choise for many "8 ohm" speakers, but 25 is a bit high.
It doesn't affect the sound at all - you just get less output power. I use a 2*15V transformer myself with "8 ohm" speakers.
Best regards,
Mikkel C. Simonsen
Poeee,
I'm from Melbourne which isn't too far from you. Don't buy the Jaycar transformer's they're not good quality and they want too much for them. I was recommended Harbuch's by a very respectable amplifier manufacturer, which make great antrim toroidal trannies of very high quality.
You can bascially order what you like - I have ultimately ordered 4 225va 22v secondary toroids twice for around $45 each plus about $10 for postage. Great quality trannies at a really good price - they use courier so you normally get them in 1 or 2 days.
I don't work for them! Just passing on my good experiences.
They've got a site - http://ourworld.compuserve.com/homepages/harbuch/
The range is unbelievable, pick whatever secondary voltage you like ( although my 6 channels of BrianGT are working very well with 22v secondaries as recommended - although my speakers are 6 ohm nominal and I'm bi-amping they work fine. I wouldn't go above 24 but would go to 20 or even 18 if I was running 4 ohm speakers. The LM3875 whitepaper is very good for working this out.
Hope this helps.
I'm from Melbourne which isn't too far from you. Don't buy the Jaycar transformer's they're not good quality and they want too much for them. I was recommended Harbuch's by a very respectable amplifier manufacturer, which make great antrim toroidal trannies of very high quality.
You can bascially order what you like - I have ultimately ordered 4 225va 22v secondary toroids twice for around $45 each plus about $10 for postage. Great quality trannies at a really good price - they use courier so you normally get them in 1 or 2 days.
I don't work for them! Just passing on my good experiences.
They've got a site - http://ourworld.compuserve.com/homepages/harbuch/
The range is unbelievable, pick whatever secondary voltage you like ( although my 6 channels of BrianGT are working very well with 22v secondaries as recommended - although my speakers are 6 ohm nominal and I'm bi-amping they work fine. I wouldn't go above 24 but would go to 20 or even 18 if I was running 4 ohm speakers. The LM3875 whitepaper is very good for working this out.
Hope this helps.
As to the pot, this is the one you should be geting: http://www.diyaudio.com/forums/showthread.php?s=&threadid=39258&highlight=
Thanks for the info, and you aren't the only people who have told me to get Harbuch transformers.
Another question... Although I will more than likely be running 8ohm speakers, there may be the chance that one day I will be running 4ohm speakers, as I have some good car audio stuff (running Hertz HSK splits in my car at the moment, which are renowned for their mid bass). So keeping that in mind, what would be the "ideal" transformer for me? Should I go with a 18v 160VA or go a bit higher in VA?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=39258&highlight= - those little pots seem like a winner, and I can get them from Jaycar. Thats WIN WIN!
Another question... Although I will more than likely be running 8ohm speakers, there may be the chance that one day I will be running 4ohm speakers, as I have some good car audio stuff (running Hertz HSK splits in my car at the moment, which are renowned for their mid bass). So keeping that in mind, what would be the "ideal" transformer for me? Should I go with a 18v 160VA or go a bit higher in VA?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=39258&highlight= - those little pots seem like a winner, and I can get them from Jaycar. Thats WIN WIN!
I would be going for 18 to 20v secondaries for 4ohm speakers. Having said that my 22v's are great. There is a graph called 'output power vs supply voltage' on the LM3875 whitepaper (page 9) which shows the ballpark that you should be aiming for).
I used the formula to keep at least 100VA per channel based on general advice on here. It seems to have worked well enough.
I used the formula to keep at least 100VA per channel based on general advice on here. It seems to have worked well enough.
I'm running on a 2*15V trannie, deffinitly too low, but it was only a test run without heatsinks, and i did not want to smoke'em.
but peter is probably right, i wasn't impressed by the sound to tell the truth. hopefully it will be better with resistors solderd directly on the legs if the ic and a 30-0-30V trafo.
regards
marius
but peter is probably right, i wasn't impressed by the sound to tell the truth. hopefully it will be better with resistors solderd directly on the legs if the ic and a 30-0-30V trafo.
regards
marius
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