Jaycar kits....

[Xicarius]

Does anyone here have experience with Jaycar electronics (Australia) and their audio kits? Such as:
http://www1.jaycar.com.au/productVie...=&SUBCATID=557

Does anyone know how good an amp it is? Also, how much difference does the transistor package make? They have the same amp with different transistor package:
http://www1.jaycar.com.au/productVie...=&SUBCATID=557

[Greg Erskine]

Hi Xicarius,

I have built a Dick Smith SC480 with TO3 output devices, but I imagine that would be almost the same as the JayCar version. Judging the performance of amp is really just one person's individual preference so don't take my opinion as gospel. I wasn't expecting much from a cheap Dick Smith kit using 2N3055/2095 output transitors and was pleasantly surprised. ($39 on special).

I imagine the alternative output transistors would improve the sound somewhat.

Mechanically, I my opinion, the SC480 pcbs are way to big and are a squeeze to fit into a 3U or 2U cabinet. The pcbs are just over 150mm wide and you need to trim them if you want to fit them on one 300mm heatsink.

Depending on your budget and expectations I would recommend an AKSA, a DIGI125 or an Elliott P3A as I have built them and prefer them to my SC480. I seem to have got stuck on building Australian amps although one or eight gainclones have snuck in.

Another option that looks interesting this month, if a class A is not a problem, is this special.

http://www.altronics.com.au/cat.asp?...=427&id=K5109S

BTW: Altronics also have the SC480 in a package deal this month that looks good value
http://www.altronics.com.au/cat.asp?...=427&id=K5120S

You probably need to state what your requirements are, as there are lots of good amps to build all with their pros and cons.

[Xicarius]

Originally posted by grege
Hi Xicarius,

I have built a Dick Smith SC480 with TO3 output devices, but I imagine that would be almost the same as the JayCar version. Judging the performance of amp is really just one person's individual preference so don't take my opinion as gospel. I wasn't expecting much from a cheap Dick Smith kit using 2N3055/2095 output transitors and was pleasantly surprised. ($39 on special).

I imagine the alternative output transistors would improve the sound somewhat.

Mechanically, I my opinion, the SC480 pcbs are way to big and are a squeeze to fit into a 3U or 2U cabinet. The pcbs are just over 150mm wide and you need to trim them if you want to fit them on one 300mm heatsink.

Depending on your budget and expectations I would recommend an AKSA, a DIGI125 or an Elliott P3A as I have built them and prefer them to my SC480. I seem to have got stuck on building Australian amps although one or eight gainclones have snuck in.

Another option that looks interesting this month, if a class A is not a problem, is this special.

http://www.altronics.com.au/cat.asp?...=427&id=K5109S

BTW: Altronics also have the SC480 in a package deal this month that looks good value
http://www.altronics.com.au/cat.asp?...=427&id=K5120S

You probably need to state what your requirements are, as there are lots of good amps to build all with their pros and cons.

Cool, thx. My requirements are still evolving, but provided my skills and budget permit I'm replacing ALL of stereo gear. Starting with the subwoofer box+amp, then ill proly build a chip amp to practise and then ill decide. What I'd like to do is build a tri amp setup, so Class A will be used for the tweeters....with a 3 way electronic crossover, I need mid and bass amps......

from the elliot site, rough rule of thumb was 20w Class A for tewwters and I think about 50w each for mid and bass, to keep eveverything closeish, then tweak gain to get it accurate....?
That about right?

The main reason I've been looking at Jaycar is a) i get wholesale and b) they supply all components and PCB. For the elliot projects, I couyld buy a PCB, but what do u think the components would set me back, roughly?

[Greg Erskine]

Xicarius, sounds like you have a good plan regarding upgrading of your system.

I didn't keep track of the costs of my Elliott P3A but I guess it would be just a little dearer than the JayCar SC480. The output devices are the most expensive item and the cost will vary upon what you decide to use. As an option, you could get some samples that cost nothing. Rod Elliott seems to design his amps around the local electronics stores catalogues so you won't have much trouble getting the components from Dick Smith, JayCar, Altronics or RS Components. I do recommend Harbuch (at Hornsby) for toroids if you're in Sydney, they are cheaper and better quality than those you get from the above suppliers.

As a side note, I thought my SC480 is a little shy on bass so be a little wary about using them for woofers. Also, the SC480 doesn't seem to have the power of my other amps even though in theory it has a higher rating. At a guess, I thought that may have something to do with most of my other amps have a boot strapped VAS. Anyway, it would be interesting if a few others could confirm my experiences before you place too emphasis on my judgement.

On the chipamp front, I can recommend the BrainGT premium kit for quality of PCB and components. They are also pretty cheap.

[Xicarius]

Originally posted by grege
Xicarius, sounds like you have a good plan regarding upgrading of your system.

I didn't keep track of the costs of my Elliott P3A but I guess it would be just a little dearer than the JayCar SC480. The output devices are the most expensive item and the cost will vary upon what you decide to use. As an option, you could get some samples that cost nothing. Rod Elliott seems to design his amps around the local electronics stores catalogues so you won't have much trouble getting the components from Dick Smith, JayCar, Altronics or RS Components. I do recommend Harbuch (at Hornsby) for toroids if you're in Sydney, they are cheaper and better quality than those you get from the above suppliers.

As a side note, I thought my SC480 is a little shy on bass so be a little wary about using them for woofers. Also, the SC480 doesn't seem to have the power of my other amps even though in theory it has a higher rating. At a guess, I thought that may have something to do with most of my other amps have a boot strapped VAS. Anyway, it would be interesting if a few others could confirm my experiences before you place too emphasis on my judgement.

On the chipamp front, I can recommend the BrainGT premium kit for quality of PCB and components. They are also pretty cheap.

3

Thanks for that! Sounds like the Elliot amps are the way to go, but b4 I dive in I think I might build a little stereo amp using the Jaycar kits (a 50w per cannel, using the chip amp not the transistors) for practise.

[Xicarius]

any other thoughts/ideas/input?

[kimbo]

For anyone who is interested in view the diagram, the entire article may be viewed by simply doing a google search using the terms 'sc480 silicon chip' and when the results are shown, click on "Cached" instead of the real link. Here is the link (I hope this works.....)

http://www.google.com.au/search?q=ca...con+chip&hl=en

http://www.google.com.au/search?q=ca...con+chip&hl=en

I have just finished stuffing a pair of these into a 3U case but can't offer an opinion re the sound as yet as I built them to break in a few speakers I wish to test before designing/building enclosures. (Can you hear them buzzing in the background??!). Will post a description with images in a few days.......but I just wanted to tell you that the Altronics kit comes with a hefty heatsink for the same cost as the Jacar without heatsink. (just in case you were planning to buy in the next few days.