Slow Blow pre?

[synthi]

I`m also finishing the La2 and the sloblo would be my next project, I`m really interested in do it as my first p2p project

Would be great have a "certified" schematic/layout... :roll:

Synthi

 

[DaxLiniere]

Sorry Kubi, but what's the point of sending me on a search when you know all the links are dead?
I am just as irritated as you if someone asks a question when there's obviously a wealth of information available via a simple site search.
But this is not the case this time.

Incidentally, I had already done that search and as I mentioned, found nothing, hence my post.

 

[FotisGR]

YEAAHHH. I am back...
Hi to all of you. Synthi i send you some files. Sysmofit links are dead.
Slowblow pre is akiller pre. Try it before you cry for it... :grin:

Fotis

 

[synthi]

Thanks Fotis! :grin:

Synthi

 

[rafafredd]

Since I know diddly-squat about transformers and their correct usage, could someone tell me about the suitability of this transformer (of which I own a few) as the input tranny for this preamp.

This transformer is so high inductance that you could try it as a 150:4k5 input at the slow blow preamp. Knowing tamura transformers, I say it will work great, at least... But probably not permalloy core, so expect color if used with low level mics.

 

[Bluzzi]

Fotis,

You are the reason I want to make this pre! I read your "orgasmic" description and now must make one (or 2).

Is it possible to post the files on your site or send me them and I will post on mine.

If others want, I can post all documents so that we all have the same files and can discuss them.

Thanks

Jim

 

[toffifee]

Cool, Fotis is back. Fotis, it would be nice if you could bring the links to your PSU schems back to life (this thread:
http://www.groupdiy.com/index.php?topic=10751&postdays=0&postorder=asc&start=0 )
I think it would be extremly helpful for future SlowBblo builders; I took those files as an inspiration for my Slowblo-PSU. Where did you end with the tubes? All 5687? Or "classic" with ECC82/5687? I have it running "classic", like it so far.
Now we only need Jazzy to post his version of the signal part (the "asymptot"). I have the file, but I would like to have the permission of Jazzy to post it (or better he posts it).
For those who think about doing this pre on a PCB: the 5687 is a very hot tube, I wonder if a PCB could stand the heat (but I am not very experienced with that).
Toff :sam:

 

[DaxLiniere]

Hooray! Hooray! It's getting under way!

 

[peterc]

I'm also looking forward to building one of these.

Extra orgasms are always welcome!

Thanks for Fotis & others effort here.

Peet

 

[Bluzzi]

This is starting to gather momentum! I think that "orgasmic" description is luring us in!

But do we have a definitive set of schematics?

Like I said before I have a bunch of documents. I could furnish the space on the web to have a central location for everything. How does that sound?

I can send whoever wants my email address in a private message.

Let me know.

jim

 

[Flundran]

Jim,

It sounds great with a space on the web with all infos on the SlowBlow. Keep us posted!

/F

 

[Bluzzi]

I'm not in Montreal this weekend but I'll try and set something up with all that I have and post the url. I am staying at a hotel and they have high speed so maybe I can do it from here.

Thing is we need to get everyone elses documents and then decide on the newest and most valid ones.

jim

 

[FotisGR]

Don't worry about shematics-infos. I have everything you need and i have build all versions. The double srppp the 2x5687 and the last one that jazzy tried,too with the 12sn7 and 5687. I promish to help everyone, just have a litle patience because i am always busy...
cheers
fotis

 

[DaxLiniere]

Thanks Fotis, you rock!

We patiently await your convenience.

 

[Bluzzi]

fotis, thanks for your help here. I'll be patiently awaiting your comments.

jim

 

[FotisGR]

OK Lets start. :thumb:

The classic (first version) shematic is here : http://www.qsl.net/sv3eao/preamp.jpg and http://www.qsl.net/sv3eao/powersupply.jpg


The second version is here : http://www.qsl.net/sv3eao/slowblow2.jpg

My project contains 2 channels. One channel is the classic slowblow and the other is like the slowblow 2 but with 5687 at the first stage instead of 12sn7. The psu is redesigned by me and is here : http://www.qsl.net/sv3eao/psu.gif

Some pics from my project are here:

http://www.qsl.net/sv3eao/Micpre/123_2353.jpg
http://www.qsl.net/sv3eao/Micpre/123_2367.jpg
http://www.qsl.net/sv3eao/Micpre/123_2371.jpg
http://www.qsl.net/sv3eao/Micpre/123_2380.jpg
http://www.qsl.net/sv3eao/Micpre/123_2397.jpg
http://www.qsl.net/sv3eao/Micpre/124_2440.jpg

My regards
fotis

 

[suprughetto]

[quote author="FotisGR"]



My project contains 2 channels. One channel is the classic slowblow and the other is like the slowblow 2 but with 5687 at the first stage instead of 12sn7.[/quote]

So which one do you prefer?
Thank you for posting this...and yes, very very very nice job!

 

[Flundran]

thanks for the links Fotis! :sam:

It would be neat to find a transformer with all three voltages needed in the PSU. I read from an old thread someone suggested the TRA200 from this company:
http://die-wuestens.de/

sec 230V 0,12A ; 20V 0.12A; 6,3V 4A.

And then use a voltage doubler for 48V and running the heaters on 6V. Is there any disadvantages with running heaters on 6V instead?

Another option is to have a transformer custom-made, but it?s pretty expensive I guess..

 

[FotisGR]

I have for sale some quality toroid trafos and chokes for this project if someone wants to buy.

The trafos are multivoltage (250VAC , 50VAC and 13VAC) 150VA enough for 10 channels psu and the chokes are 10H/150mA - 65Ohm.
These are that i use on the pictures of my project.
The prices are 45Euros for main trafo and 25Euros for each choke.
If i can remember from Jazzy's order the delivery cost was about 10Euros (from Greece to France).

I will come back later...
fotis

 

[Bauman]

Thanks! Look forward to build one!