line pre's?

[jeth]

Greetings once again..
I'm looking at circuits for line level inputs (unbalanced) for a mixer project. I want something simple, preferably discreet or op-amp based, no tubes or trafos as I simply don't have the resources at this time-I hope to take experiments in that direction once I'm back in the UK where I have numerous boxes full of old mixer boards to scavenge. For now I just want a reasonable quality circuit to work on my layout.
This place is full of all manner of mic pres and so are other sources online, but it seems that there is little on offer for line pres apart from the standard op-amp buffer configuration. Is it just that the circuit is not so critical at the lower gain required, or is there some middle ground out there to be found?
What would be really nice is if someone could point me towards any relevant articles that explain the pros, cons and workings of different designs. Or maybe all I need is a straight forward line buffer?

 

[Svart]

I haven't been able to find the 1512 anywhere.. got a supplier?

 

[NewYorkDave]

Check out the good ol' "Superbal" input stage. You can implement it quite nicely with a single 5532.

 

[CJ]

jeth, take a gander here:

http://sound.westhost.com/index2.html

 

[jeth]

Thanks for all the suggestions.

Had a look at the THAT1510 chips, nice, but I really don't think I can get my hands on anything like that in my present location. (Deep south mexico) Too broke to order a quantity from elsewhere.

Found the superbal on the forum but I'm really looking for an unbalanced stage. Seems silly to build balanced ins if i don't need them.

Kubi, did you mean something like this?

And Cj..familiar with the esp site..exactly what made me wonder if all i needed was a simple opamp buffer as used in most of those projects.

Thanks again for your input(s) ..I'd be even more ignorant without folks like you.

 

[CJ]

hey jeth, how did you do the thumbnail thing?

 

[Consul]

http://imageshack.us/

:thumb:

 

[CJ]

oh cool!
can I code that into my own images without the site?
hammer and chisel software approach i imagine?

 

[Consul]

It would be possible to do, but a lot of work coding it.

iPowerWeb supports the use of a program called Gallery, which does things like automated thumbnail generation. Ask their support staff about it, they can tell you how to set it up and use it.

 

[PRR]

> can I code that into my own images without the site?

You need to save and host the image in both sizes, huge and thumbnail. (If you went into this big-time, you would rig up a script to generate the thumbnail on the fly; that's probably more work than you want to get into.)

This small pic will open a bigger pic when you click:


Code, except with made-up server and file names:

[url=http://cj.com/radio.gif][IMG]http://cj.com/radio-small.gif[/IMG][/url]

 

[skipwave]

Thanks PRR, I've been wondering how to do the image/link combination here.

I use a PERL module called PhotoAlbum.pm (details at nateware.com) that does the whole photo album with thumbnails thing, although you still have to generate two images. I was working on one that would allow my relatives to upload images, automatically resizing and compressing them since most of the relatives don't know how. It would also automatically generate the thumbnail. I didn't get that far into it, and PERL is probably not the best language for it anyway.

Is that image the beach radio of Edwin Howard Armstrong?

 

[rafafredd]

sometime ago the auto image_size_crop or whatever you call it was turned on, and it made things really eas here. Ethan, can it be turned on again? Or did it caused problems?

 

[PRR]

> Or did it cause problems?

It was as much trouble as it was worth.

It nearly doubled the load on the wires and our image-servers, since the forum fetched the file to check the size, and then your browser fetched the file to display.

If the image server were off-line, or very slow, the resize algorithm just hung. Whole threads couldn't be opened. I think that happened once too often; Ethan has a Life, he can't be spending the whole day un-sticking the threads.

The real answer is for member to have a little common courtesy, even if it does take a little more effort.