I'm just getting all the parts together that I need to build the thing. I'm from the UK, and can't find the LM3875 that everyone seems to like. I'd probably get the chip from Maplins, thier selection is as follows:
http://www.maplin.co.uk/search.aspx...mMenu=y&criteria=POWER AMPS&doy=2m1&worldid=3
So far, the one I think is more appropriate is the first one on that page, the LM380N. Does anyone have any suggestions? I assume I need 2 of the chips? For stereo sound.
I have another question about the right transformer to get. Suppose I did use 2 of the above chips, from the datasheet it says high peak current capability is 1.3A, and supply voltage is 10-22v. Does that mean I'd need a transformer with an output VA of 22 * 1.3 * 2 ~ 60?
Many thanks.
http://www.maplin.co.uk/search.aspx...mMenu=y&criteria=POWER AMPS&doy=2m1&worldid=3
So far, the one I think is more appropriate is the first one on that page, the LM380N. Does anyone have any suggestions? I assume I need 2 of the chips? For stereo sound.
I have another question about the right transformer to get. Suppose I did use 2 of the above chips, from the datasheet it says high peak current capability is 1.3A, and supply voltage is 10-22v. Does that mean I'd need a transformer with an output VA of 22 * 1.3 * 2 ~ 60?
Many thanks.
Try RS like Nordic suggested or if you are willing to try the 3886 then try www.Madaboutsound.com
Thanks for the replys.
I looked at the Mad about Sound website, but it involves me buying a £15:28 amp kit, which is not what I really want to spend for a chip. I want to build the thing myself, rather than from a kit. Do you know of any other places where I can get just the chip?
Nordic, do the sites you suggested have a minimum order amount? Or large postage cost? I suggested Maplin as I can get into the shop, and therefore not have to pay any postage. I also have all the other components I need (other than a transformer) to build the amp, therefore a £20 order (for example) would be a waste of money for a chip.
Many thanks.
I looked at the Mad about Sound website, but it involves me buying a £15:28 amp kit, which is not what I really want to spend for a chip. I want to build the thing myself, rather than from a kit. Do you know of any other places where I can get just the chip?
Nordic, do the sites you suggested have a minimum order amount? Or large postage cost? I suggested Maplin as I can get into the shop, and therefore not have to pay any postage. I also have all the other components I need (other than a transformer) to build the amp, therefore a £20 order (for example) would be a waste of money for a chip.
Many thanks.
No minimum order at RS, although some components you have to buy in quantities of 5 or so... those chips you can buy in singles... I got one from them a few weeks ago...
Also see if they don't have a trade counter in your area... then you can pick up without paying for postage...that is what I do... if it works all they way down in Africa, it should be no hassle over there... in fact you never have to wait for ex UK stock like me...
Also see if they don't have a trade counter in your area... then you can pick up without paying for postage...that is what I do... if it works all they way down in Africa, it should be no hassle over there... in fact you never have to wait for ex UK stock like me...
If you are going to order from RS make sure you do it online otherwise there may be a £3.50 handling charge, the £20 minimum only applies to phone, fax and email orders.
I am going to place an order for some pre-amp components in the next week, if you can wait that long I can add a couple of 3875 chips in my order and post them to you when I get them (assuming no one else offers you some before then). Then you can just send me a cheque or a paypal payment.
Cheers,
Ian
I am going to place an order for some pre-amp components in the next week, if you can wait that long I can add a couple of 3875 chips in my order and post them to you when I get them (assuming no one else offers you some before then). Then you can just send me a cheque or a paypal payment.
Cheers,
Ian
Thanks for all the replys.
I have emailed Mad about Sound, waiting for a reply. They seem to be out of stock on the RS site, so I guess i'll have to wait. Ian, that's a very generous offer, thank you very much. However if there isn't a minimum order cost or postage cost is there an advantage in combining orders?
Am I right in thinking I will need 2 chips, for stereo sound?
And finally, what transformer would you advise me to get? Probably from RS as there is no postage cost. I'm in the UK so 240v input.
Many thanks.
I have emailed Mad about Sound, waiting for a reply. They seem to be out of stock on the RS site, so I guess i'll have to wait. Ian, that's a very generous offer, thank you very much. However if there isn't a minimum order cost or postage cost is there an advantage in combining orders?
Am I right in thinking I will need 2 chips, for stereo sound?
And finally, what transformer would you advise me to get? Probably from RS as there is no postage cost. I'm in the UK so 240v input.
Many thanks.
Hi Mat, no problem on the offer it was just an ease of you registering, etc etc. I am not sure if there are postage costs for orders under a certain value (you can imagine they would get annoyed if you ordered a couple of resitors every other day!)
There is the 4780, which can be used for a stereo chipamp, as it effictively combines two 3875s in one package.
As for transformers, the advice given above looks good, I am using the potted 300VA version that mad about sound sell and I am very impressed, they are the quietest and coolest running transformer I have come across.
There is the 4780, which can be used for a stereo chipamp, as it effictively combines two 3875s in one package.
As for transformers, the advice given above looks good, I am using the potted 300VA version that mad about sound sell and I am very impressed, they are the quietest and coolest running transformer I have come across.
Ian, I couldnt find the 4780 on the site, do you have a link? I have since found out that postage would cost me about £5. I'll have a look round and see if there are any other places, but sharing an order with you sounds good at the moment, if we split the postage?
Vikash, thanks for the email. However, by the time I've bought the chips and payed postage it will become pretty expensive, so I may have to pass. Thanks anyway.
Would 150Va be enough for the transformer? I have 8 ohm speakers, never have the volume very load, and deffinately not for long periods of time.
Does anyone else have any views on the TDA2050? That's pretty tempting for me, and deffinately the cheapest option at the moment.
For a 24v secondary coil, does that mean the power on the rails will be 24 * 1.4 *0.5 ~ +-17v? Is that enough to power the chip?
Many thanks for all the replies so far, really helpful
Vikash, thanks for the email. However, by the time I've bought the chips and payed postage it will become pretty expensive, so I may have to pass. Thanks anyway.
Would 150Va be enough for the transformer? I have 8 ohm speakers, never have the volume very load, and deffinately not for long periods of time.
Does anyone else have any views on the TDA2050? That's pretty tempting for me, and deffinately the cheapest option at the moment.
For a 24v secondary coil, does that mean the power on the rails will be 24 * 1.4 *0.5 ~ +-17v? Is that enough to power the chip?
Many thanks for all the replies so far, really helpful
Thanks for the link Nuuk. Very helpful. One thing I didn't understand:
"I suggest a minimum of 120VA if you use just one transformer, or 80VA if you use one transformer for each channel"
Does "one transformer for each channel" mean just 2 secondary coils? Or literally 2 seperate transformers entierly.
Nordic, there is a trade counter which I 'could' get to if needed when I go back to Uni, but the amount of effort is pretty much equal to half the postage cost.
Ian, where on RS is the LM4780. I searched for it but couldn't see it there. E-mail me at matheprat AT hotmail.com and we can arrange it. I couldn't get your address off here.
Many thanks.
"I suggest a minimum of 120VA if you use just one transformer, or 80VA if you use one transformer for each channel"
Does "one transformer for each channel" mean just 2 secondary coils? Or literally 2 seperate transformers entierly.
Nordic, there is a trade counter which I 'could' get to if needed when I go back to Uni, but the amount of effort is pretty much equal to half the postage cost.
Ian, where on RS is the LM4780. I searched for it but couldn't see it there. E-mail me at matheprat AT hotmail.com and we can arrange it. I couldn't get your address off here.
Many thanks.
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