Can someone advise me on a chip for a gainclone? (In the UK)

matheprat · 2nd January 2007, 07:01 PM

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?...=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.

Nordic · 2nd January 2007, 07:11 PM

You should have no problem ordering from farnell or even rs components... they are uk based, but i regularly get stuff from them...

ianpengelly · 2nd January 2007, 09:21 PM

Try RS like Nordic suggested or if you are willing to try the 3886 then try www.Madaboutsound.com

matheprat · 2nd January 2007, 11:51 PM

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.

pinkmouse · 3rd January 2007, 12:04 AM

The 380 isn't really much cop for anything apart from headphones, and I have never used the TDA chips, so can't comment on those. Drop Vikash a line, he may well have spares of the LMs.

ianpengelly · 3rd January 2007, 06:04 AM

Hi Pinkmouse, you beat me to it!

I was going to say drop madaboutsound an email and ask if they would supply just a chip/chips, Vikash (on this forum) runs madabout sound.

Nordic · 3rd January 2007, 06:45 AM

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...

ianpengelly · 3rd January 2007, 08:44 AM

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

Vikash · 3rd January 2007, 11:24 AM

Hi Mat, I've replied to your email.

Yes each chip is single channel, so you will need 2 for stereo. Any dual secondary toroidal with greater than 160 VA will suffice. Look for secondary voltage rating of between 18v and 24v.

matheprat · 3rd January 2007, 11:28 AM

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.

2nd January 2007, 07:01 PM	#1
matheprat diyAudio Member Join Date: Jan 2007	Can someone advise me on a chip for a gainclone? (In the UK) 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?...=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.

3rd January 2007, 12:04 AM	#5
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	The 380 isn't really much cop for anything apart from headphones, and I have never used the TDA chips, so can't comment on those. Drop Vikash a line, he may well have spares of the LMs. __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

3rd January 2007, 11:24 AM	#9
Vikash diyAudio Moderator Emeritus Join Date: May 2003 Location: UK	Hi Mat, I've replied to your email. Yes each chip is single channel, so you will need 2 for stereo. Any dual secondary toroidal with greater than 160 VA will suffice. Look for secondary voltage rating of between 18v and 24v. __________________ "The human mind is so constituted that it colours with its own previous conceptions any new notion that presents itself for acceptance." - J. Wilhelm. (But I still think mine sounds better than yours.)

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2nd January 2007, 07:11 PM	#2
Nordic diyAudio Member Join Date: Sep 2005	You should have no problem ordering from farnell or even rs components... they are uk based, but i regularly get stuff from them...

2nd January 2007, 09:21 PM	#3
ianpengelly diyAudio Member Join Date: Oct 2006	Try RS like Nordic suggested or if you are willing to try the 3886 then try www.Madaboutsound.com

2nd January 2007, 11:51 PM	#4
matheprat diyAudio Member Join Date: Jan 2007	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.

3rd January 2007, 06:04 AM	#6
ianpengelly diyAudio Member Join Date: Oct 2006	Hi Pinkmouse, you beat me to it! I was going to say drop madaboutsound an email and ask if they would supply just a chip/chips, Vikash (on this forum) runs madabout sound.

3rd January 2007, 06:45 AM	#7
Nordic diyAudio Member Join Date: Sep 2005	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...

3rd January 2007, 08:44 AM	#8
ianpengelly diyAudio Member Join Date: Oct 2006	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

3rd January 2007, 11:28 AM	#10
matheprat diyAudio Member Join Date: Jan 2007	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.

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