78 equalization?

[Justinasia]

Hello!
I want to make a preamp for 78 speed records. I know they use many different equalization curves. It seems that there are no kits for making such a preamp. I have seen nice looking comercial products but very expensive, such as:

http://www.vadlyd.dk/English/RIAA_an...PM_preamp.html

Someone in another thread posted a link to a circuit diagram of a preamp that might work. But, I cannot understand just circuit diagrams. If people think it looks good, how can I build or learn to build it just from this diagram?

http://www.rfwilmut.clara.net/repro78/circuit.html

Or, perhaps there is a simpler way to do this? I am sorry I am so ignorant - I don't know how these different curves are made by the preamps. But, is it possible to have a preamp with a few knobs that you can turn, to vary different factors of whatever is making those curves? So that way be able to manually create the different curves and anything in between? (As I heard many people didn't even stick to the various official curves anyway).

For example, would any of you out there like to design a nice simple preamp like that, with some knobs to vary the curves? That could be very nice right!

Best wishes
Justin

[sreten]

Hi, http://sound.westhost.com/project91.htm , /sreten.

[hagtech]

Kit:

www.hagtech.com/bugle.html

[dvautier]

Just a thought on early equalization
.

I got a bunch of real old 78s from my parent’s estate. I digitized about 60 and afterwards did some approximate equalization. I then compared a few “Two Black Crows” numbers with some remastered stuff I have on vinyl. With records made in the 1920s I don’t know if there is any equalization that works. What I usually did was bump up the 4 to 6 kHz range and cut off anything above 8 kHz. Seems there is nothing up there except noise.

Anyway here is a link to some of my feeble efforts.

http://dvautier.home.comcast.net/records/records.htm

[Justinasia]

Originally posted by hagtech
Kit:

www.hagtech.com/bugle.html

Hello
Does the power supply work in Japan? And has anyone tried this preamp? The reviews seem to be for the Bugle rather than Bugle pro. It would be ice to hear a review written by someone who is actually usuing the variable eq., i.e. for 78s.
Thanks
Justin

[hagtech]

The Bugle Pro uses the same circuit board as the Bugle, but with the switchable resistors and capacitors for variable EQ added. So they should sound pretty much the same. A BP also fared well at the phono shootout at ETF05. Yes, it will run at 100Vac.

Oh, I forgot, this one is even better:

www.hagtech.com/pdf/monogram.pdf

Then someone pointed out this new machine to me (but it is not DIY):

http://www.toneimports.com/sentec/sentec_eq10.html

jh

[Justinasia]

Originally posted by hagtech
The Bugle Pro uses the same circuit board as the Bugle, but with the switchable resistors and capacitors for variable EQ added. So they should sound pretty much the same. A BP also fared well at the phono shootout at ETF05. Yes, it will run at 100Vac.

Oh, I forgot, this one is even better:

www.hagtech.com/pdf/monogram.pdf

Then someone pointed out this new machine to me (but it is not DIY):

http://www.toneimports.com/sentec/sentec_eq10.html

jh

How much does the monogram cost? I can see no reference to it on your website. (Also I can seee no price anywhere for the Sentec either. Looks good.)
Thanks
Justin

[hagtech]

How much does the monogram cost?

Depends on the parts you use. It is NOT a product I sell. Merely a fully debugged and tweaked schematic I offer to the DIY crowd.

jh

[Justinasia]

Originally posted by hagtech


Depends on the parts you use. It is NOT a product I sell. Merely a fully debugged and tweaked schematic I offer to the DIY crowd.

jh

Oh I see. That's very noble of you. How much do you think it cost cost for all the parts? Like, from what to what, reasonably speaking? And do you sell the pcbs for it?
Many thanks
Justin

[hagtech]

Well, the first paragraph of the article mentions cost. As far as PCBs go, you can contact me offline.

jh