Kit?

bjackson · 23rd April 2005, 03:07 AM

Is there such a thing as an amplifier kit for a gainclone. I have seen PCBs, but I get confused as to the transformer, etc, needed, and I wanted to know if there was a pre-existing solution.

Also, what can you expect to pay for them considering the following, assuming standard components and nothing 'special'.

I need one that can do atleast 20wrms @ 8ohms x 2, if not a bit higher, and I need one that can do atleast 80wrms, hopefully around 100wrms @ 4 ohms x 2. I'd like to make this all in one chassis. They will be driven off an external rane ac23 crossover.

I am sorry for the newbie questions but I have searched and not found anything specific to my problems.

Would I get similar results from buying off the shelf used Yamaha Natural Sounds (looks like a pyramid almost) amplifier, or a Kenwood Basic M2 (200wrms x 2 @ 8 ohm), which are 125, and 225 respectivly at a local audio shop.

If I could make something for less or the same that would be higher quality, I wouldn't mind spending the time to make quality, although I have never soldered in my life, it's something I really need to get to learning.

chipco3434 · 23rd April 2005, 03:23 AM

chipamp.com

Buy the boards, read the manual, order "stuff" from partsexpress.com and radio shack.

Quote:

Yamaha Natural Sounds (looks like a pyramid almost) amplifier, or a Kenwood Basic M2 (200wrms x 2 @ 8 ohm),

who cares... these aren't DIY

Quote:

Would I get similar results

No, you would have no self-fulfilment and would appear as if you were every other dweeb as opposed to one of the cool guys.

bjackson · 23rd April 2005, 03:26 AM

I have seen those (actually spent a lot of time reading the manual), and I still can't figure out what kind of transformer I'd need. Well that's not completly true, I figured out what I need, but I can't find where to buy it. I tried digi-key and got confused. So I was looking into an integrated solution and

HOW MUCH WILL THIS COST ME ALL TOGETHER.

No one will answer this fundamental question which is really the deciding factor for me :-)

jleaman · 23rd April 2005, 03:31 AM

Quote:

Originally posted by bjackson
I have seen those (actually spent a lot of time reading the manual), and I still can't figure out what kind of transformer I'd need. Well that's not completly true, I figured out what I need, but I can't find where to buy it. I tried digi-key and got confused. So I was looking into an integrated solution and

HOW MUCH WILL THIS COST ME ALL TOGETHER.

No one will answer this fundamental question which is really the deciding factor for me :-)

Email me and ill help you..

put in the subject chip amp help..

J'

chipco3434 · 23rd April 2005, 03:42 AM

This hobby isn't for everybody.

Read this three times...Brian's 3875 manual

Then buy a transformer, a fuse block, a pot, and two chunks of aluminum, a switch, a soldering iron and two bucks worth of solder.

Quote:

HOW MUCH WILL THIS COST ME ALL TOGETHER.

A hundred bucks.

What will the value be?

More, much more.

dsavitsk · 23rd April 2005, 04:55 AM

Order the transformer from partsexpress, as was mentioned above.

lgreen · 23rd April 2005, 09:49 PM

Here is the xformer I used: Parts Express Avel Lind.

Its good for 2 or maybe 4 channels. As you see you will be at over $70 just for 1 xformer (12 plus for shipping). Also, the boards are set for 1 xformer per channel so you need to play with the diode locations and short circuit a bunch of stuff to use this center-tapped xformer for all channels-- its in the 3875 user's guide on page 15. So with the $50 kit for the boards you are at $120 without any connectors, mounting hardware, switches, etc...

This is only for 2 channels, you want another 100x2 which means you need 2 more kits to parallel some amps up as no chips give you this much power. Add another $100 right off the top, and get a bigger xformer. So you are over $220 easily. Maybe for what you wan't I'd expect to pay $300 by the time its all over; possibly much more.

You will need to get wire, solder, an iron, a case, parts, connectors, a ton of stuff, and you will get something that doesn't go as loud as your Yamaha and which looks kind of like you made it in your garage, which you did. This is not really a money saving way to do it, especially since you want to make a couple of them. You should proceed if you want to learn something and if you enjoy building your own stuff; you won't save all that much (if any) money.

x. onasis · 24th April 2005, 03:00 PM

Wouldn't that 500VA toroid linked above, power both a 3875 and a 4780 kit in the same case and give him the watts he's looking for?

Granted, wires, pots, connectors, chassis and heatsinks can add up, but it doesn't have to be "possibly much more" than about $100, does it?

I don't mean to be argumentative since this clearly adds up to about $300 at the least. AND it could be the beginning of an addiction that $ome of us know all too well.....But still, if you had that want, which direction would you take?

I'm with Chipco and Jleaman, keep posting Bjackson, and I'll help with that last $100.

edjosh23 · 24th April 2005, 04:00 PM

Quote:

Originally posted by x. onasis
Wouldn't that 500VA toroid linked above, power both a 3875 and a 4780 kit in the same case and give him the watts he's looking for?

Granted, wires, pots, connectors, chassis and heatsinks can add up, but it doesn't have to be "possibly much more" than about $100, does it?

I don't mean to be argumentative since this clearly adds up to about $300 at the least. AND it could be the beginning of an addiction that $ome of us know all too well.....But still, if you had that want, which direction would you take?

I'm with Chipco and Jleaman, keep posting Bjackson, and I'll help with that last $100.

I agree, go with a 3875 or a 3886 and then for the 100w go with the 4780s. And do get the amount of power you want, than don't max out your chips with high voltages, I'm guessing for say the 3875 you would only need about 35vdc, just a guess? If 35vdc is correct than your toroid would only have to be 25vAC at the secondaries.

After your chassis, amp kits, torroids, wire, and connections I'd say your atleast up in the $300s. You can also benifit from group buys and other inexpensive components others have found.

If this is not for an active system and you have a preamp you will save about $40+ on a 4 gang potentiometer.

Do you have any diy experience? These amps are superizingly easy to build even if you have no prior experience. Don't be afraid to search and dig up past information.

Just keep asking questions,
hope this is helpful,

Josh

bjackson · 24th April 2005, 06:12 PM

What do you mean by "if they are not active".

My reason for asking this is I am actively triamping my newly made DIY speakers, and my tweeters can handle 15 watts RMS, but I'd like a little headroom, and my mids can handle 100wrms. I have a preamp in the way of my source is a computer, and the soundcard is a pretty decent one (M-audio Revolution 7.1), that will be driving a Rane AC-23 active x-over, which then will drive the amplifiers.

I have DIY experiance as far as speaker construction goes (as I just finished my speakers :-)), but none as far as electronics go, although this would be a good experiance, I think to learn more about how an amplifier works and how to repair one since I spend way too much time and money on this hobby anyway :-)

Thanks for all the suggestions, and help everyone. I think this is the most helpful a board I have ever seen :-).

23rd April 2005, 03:07 AM	#1
bjackson diyAudio Member Join Date: Dec 2004 Location: Illinois	Kit? Is there such a thing as an amplifier kit for a gainclone. I have seen PCBs, but I get confused as to the transformer, etc, needed, and I wanted to know if there was a pre-existing solution. Also, what can you expect to pay for them considering the following, assuming standard components and nothing 'special'. I need one that can do atleast 20wrms @ 8ohms x 2, if not a bit higher, and I need one that can do atleast 80wrms, hopefully around 100wrms @ 4 ohms x 2. I'd like to make this all in one chassis. They will be driven off an external rane ac23 crossover. I am sorry for the newbie questions but I have searched and not found anything specific to my problems. Would I get similar results from buying off the shelf used Yamaha Natural Sounds (looks like a pyramid almost) amplifier, or a Kenwood Basic M2 (200wrms x 2 @ 8 ohm), which are 125, and 225 respectivly at a local audio shop. If I could make something for less or the same that would be higher quality, I wouldn't mind spending the time to make quality, although I have never soldered in my life, it's something I really need to get to learning.

23rd April 2005, 09:49 PM	#7
lgreen diyAudio Member Join Date: May 2003 Location: San Diego, USA	Cost Here is the xformer I used: Parts Express Avel Lind. Its good for 2 or maybe 4 channels. As you see you will be at over $70 just for 1 xformer (12 plus for shipping). Also, the boards are set for 1 xformer per channel so you need to play with the diode locations and short circuit a bunch of stuff to use this center-tapped xformer for all channels-- its in the 3875 user's guide on page 15. So with the $50 kit for the boards you are at $120 without any connectors, mounting hardware, switches, etc... This is only for 2 channels, you want another 100x2 which means you need 2 more kits to parallel some amps up as no chips give you this much power. Add another $100 right off the top, and get a bigger xformer. So you are over $220 easily. Maybe for what you wan't I'd expect to pay $300 by the time its all over; possibly much more. You will need to get wire, solder, an iron, a case, parts, connectors, a ton of stuff, and you will get something that doesn't go as loud as your Yamaha and which looks kind of like you made it in your garage, which you did. This is not really a money saving way to do it, especially since you want to make a couple of them. You should proceed if you want to learn something and if you enjoy building your own stuff; you won't save all that much (if any) money.

24th April 2005, 03:00 PM	#8
x. onasis diyAudio Member Join Date: Jan 2003 Location: NYS	Wouldn't that 500VA toroid linked above, power both a 3875 and a 4780 kit in the same case and give him the watts he's looking for? Granted, wires, pots, connectors, chassis and heatsinks can add up, but it doesn't have to be "possibly much more" than about $100, does it? I don't mean to be argumentative since this clearly adds up to about $300 at the least. AND it could be the beginning of an addiction that $ome of us know all too well.....But still, if you had that want, which direction would you take? I'm with Chipco and Jleaman, keep posting Bjackson, and I'll help with that last $100. __________________ onasis

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23rd April 2005, 03:26 AM	#3
bjackson diyAudio Member Join Date: Dec 2004 Location: Illinois	I have seen those (actually spent a lot of time reading the manual), and I still can't figure out what kind of transformer I'd need. Well that's not completly true, I figured out what I need, but I can't find where to buy it. I tried digi-key and got confused. So I was looking into an integrated solution and HOW MUCH WILL THIS COST ME ALL TOGETHER. No one will answer this fundamental question which is really the deciding factor for me :-)

23rd April 2005, 04:55 AM	#6
dsavitsk diyAudio Member Join Date: Jan 2005 Location: Chicago	Order the transformer from partsexpress, as was mentioned above.

24th April 2005, 06:12 PM	#10
bjackson diyAudio Member Join Date: Dec 2004 Location: Illinois	What do you mean by "if they are not active". My reason for asking this is I am actively triamping my newly made DIY speakers, and my tweeters can handle 15 watts RMS, but I'd like a little headroom, and my mids can handle 100wrms. I have a preamp in the way of my source is a computer, and the soundcard is a pretty decent one (M-audio Revolution 7.1), that will be driving a Rane AC-23 active x-over, which then will drive the amplifiers. I have DIY experiance as far as speaker construction goes (as I just finished my speakers :-)), but none as far as electronics go, although this would be a good experiance, I think to learn more about how an amplifier works and how to repair one since I spend way too much time and money on this hobby anyway :-) Thanks for all the suggestions, and help everyone. I think this is the most helpful a board I have ever seen :-).