Group order of non-inverted LM3875 pc boards? Anyone interested?

[MereGT]

I ain't seen nothing yet

All international orders are shipped USPS global priority mail, which takes 4-6 days. I don't know if that's 4-6 business days or not. Your order was shipped out last Tuesday (don't listen to brian, he doesn't bring the packages to the post office ). Hopefully your package should be there very soon! Sorry for any inconvenience!

 

[planet10]

I don't know if that's 4-6 business days or not

business days -- that means they don't have to count Saturdays & Sundays, and can look good when the package travels over the WE anyway.

dave

 

[AR2]

Thank you Brian,
I just received my order.
I am just thankfull for all the efforts you put in this group order. Everything is looking great, and PCBs are just awsome. I am sure it took a lots a work, and I just want to tell you how much I respect all you did.
Sincerely
AR2

 

[BrianGT]

Thank you Brian,
I just received my order.
I am just thankfull for all the efforts you put in this group order. Everything is looking great, and PCBs are just awsome. I am sure it took a lots a work, and I just want to tell you how much I respect all you did.
Sincerely
AR2

Thanks, I hope you enjoy them, and post pictures of a finished project soon. Don't forget that Meredith did a lot of work shipping out all the orders also.

--
Brian

 

[matt4321]

While waiting for the PCB's

Don't try this at home. I've been reading and collecting parts to make a chip amp and after trying to do it part to part and breaking a pin to 2 on my first try i decided to order pcb's. But since i had the parts this is what i got to fit into this little case. It work great except for a slight buzz in the transformer. Output is very quiet. Plan to use it in my garage. Used all carbon composite in PeterD's G2 design. 50K dual gain. 20-0-20 transformer 2 rectifiers. It barely fits and is a mess of wires. The PCB's should make my next one alot cleaner.

 

[lieven]

thanks meredith, just trying to explain how much i'm looking forward to it, not complaining at all, very greatfull for the wonderfull work you've done.

 

[Lee35210]

Thanks Brian!

Got my kit over the weekend while I was out of town. Can't wait to get started! Wish all my parts orders came as well packed,
Thanks for all your(and Meredith's) hard work and time.

Lee35210

 

[net-david]

Power amp

What changes would be needed to convert the MereBriGT gainclone from an integrated amp with volume control to a straight power amp? I know to replace the input pot with a fixed value resistor of say 22-100k, but wouldn't the gain of the amp need to be reduced? What the heck is the gain of this amp in it's current configuration? My math has it as (22k+220)/680=32.67. Seems like of the commercial amps I have seen a gain factor documented it is usually around 30, so perhaps we are already at the right configuration.

David

 

[BrianGT]

Re: Power amp

What changes would be needed to convert the MereBriGT gainclone from an integrated amp with volume control to a straight power amp? I know to replace the input pot with a fixed value resistor of say 22-100k, but wouldn't the gain of the amp need to be reduced? What the heck is the gain of this amp in it's current configuration? My math has it as (22k+220)/680=32.67. Seems like of the commercial amps I have seen a gain factor documented it is usually around 30, so perhaps we are already at the right configuration.

David

The kit is already configured to work fine without an integrated volume control. There should be no problems driving it with a preamp instead, as a straight power amp.

--
Brian

 

[Peter Daniel]

Actualy Brian's board is not an integrated amp's design. It is purely a mono amplification stage. It becomes integrated when you start adding volume controls and source selectors. But if you use a board alone you will have a straight power amp (no additional mods required).

 

[debije]

Hi Brian,

I just received my kits today. Thanks a lot for all the work you put into this.

Rob.

 

[PHR]

Thanks

Thanks Brian and Meredith, I got my kits today in perfect condition

PHR

 

[kestrel200]

Got MY KIT!!! It's great. thanks Brian & Meredith!!!!

BTW how difficult would it be to bridge two boards per channel to come up with a 100 watt per channel power amp? Are there any sites that talk about doing this sort of thing?

 

[X.G.]

BrianGT

Thanks your sharing PCB design.

I want to know :Could I make some PCBs for me and my friends according to your design(not for business).IF not,could I do that by modifying your PCB?

thx again.

X.G

 

[stadams]

It's been discussed here a few times...

BTW how difficult would it be to bridge two boards per channel to come up with a 100 watt per channel power amp? Are there any sites that talk about doing this sort of thing?

Kestrel2000,

Check out these links:

Bridgeclone
Overture Series High-Power Solutions.

I think a few people have worked on it around here. Brian shows an interesting proposition near the end of the first link.

Later,

 

[BrianGT]

BrianGT

Thanks your sharing PCB design.

I want to know :Could I make some PCBs for me and my friends according to your design(not for business).IF not,could I do that by modifying your PCB?

thx again.

X.G

You are welcome to copy it if you are not selling pcbs based on it. I will not be providing my pcb layout files for this project.

--
Brian

 

[BrianGT]

Re: It's been discussed here a few times...

Kestrel2000,

Check out these links:

Bridgeclone
Overture Series High-Power Solutions.

I think a few people have worked on it around here. Brian shows an interesting proposition near the end of the first link.

Later,

I am going to try this out, hopefully soon after I get all the orders shipped out. I am aiming to get most of them finished tonight, as I finally got the last order of the resistors needed for the kits.

--
Brian

 

[Da5id4Vz]

Hey Brian,

Perhaps I missed this in another thread, I've been wondering if you’ve made any measurements of the output of this amp?

-Dave

 

[J2JD]

Hey Brian,

Perhaps I missed this in another thread, I've been wondering if you’ve made any measurements of the output of this amp?

-Dave

http://www.diyaudio.com/forums/showthread.php?postid=352262#post352262

 

[Da5id4Vz]

Yah,

I saw that. I was thinking more like actual measurements of this LM3875 card as most of us are building it, not bridged mode. I was also wondering how the measurements would compare to published specs.