Intact Audio

wow

clarifying: I meant built-up components, not DIY parts, basically I was referring to the Pultec unit.

-j

Don't freak out . . . Maybe you should, hmm . . . . On the one hand: The only commercial inductor-based RIAA units are long ago out of production. On the other hand: They were top-shelf studio gear, used in radio stations etc., or low-production semi-DIY products. Anyway, doing an inductor-based RIA...

You're REALLY gonna be able to get THIS through the airport scanner for next year's ETF, oh yeah.

-j

Let me help you a little with that golden ratio calculation, AudioGeek!

ø~=1.6180339887498948482045868343656 . . .

ø=1+1/1·1-1/1·2+1/2·3-1/3·5+1/5·8-1/8·13+ . . . .

ø=[1+(sqrt(5))]/2

In a word, yes.

Steve - I use a step-up (Altec 15095) 1:10, any problem with that? My Denon DL103D seems happy with the ~470R reflected load.

-j

Sounds like you're gonna give the Eurotrash a treat, Steve.

-j, wishing he was further West right now

There's a perfect example of why you whistle for Steve when you're stuck.

Thanks, man!

-j

J - are there any sites you are aware of with the basics on constant impedence networks ??? Simon, I wish there was. I may be able to scan some info on the phono LCR filter bt I am having some computer problems of late that may make it hard to get to that job - let me try and find the info first, I...

I *think* if you don't want to use a buffer you could use a constant-impedance network. I dunno about that but I bet Bench does . . . he knows quite a whole hell of a lot.

-j

I've been wondering when reports would start coming in on Aikido drivers. I just replaced the output coupling caps on my Aikido line stage last night with better ones (I had just thrown any old junk box parts in at first) and the sound is now just fabulous. Should make a terrific driver with the low...

So I've been working on a BLOG, just like everybody else in cyberworld.
http://tubegeek.blogspot.com/
Some info on the phono preamp is there. I got it working today.

-j

We're totally threadjacking here, too.

-j

John's preamp is the Artemis Labs PH-1 and info can be downloaded here: http://www.artemislabs.com/docs/PH1_Manual_1.pdf There are no component values on the schematic but that's not going to stop US. Rgearding 0 bias, how much DC current would it take to toast an expensive MM cartridge? Maybe it's ...

LynnO: I'm very interested to hear that you, too were impressed with John's phono preamp. I had gotten an email from Chris Boettcher saying that that pre transformed vinyl into a completely new medium - pretty strong praise! Anyway that piqued my interest and I wrote to John and started thinking wha...

jeremy would say . . . . . . if you get it right (for your ears!) you'll know it. I'll try the L in series with the 100K on the 6SN7 plate when I can get away from listening. I'm going to enjoy the fruits of my labor for a little while. That's what I'm talking about: if you would rather listen than...

The circuit is exactly the same as the monkey, it is just drawn a bit differently. Of course you are exactly right. I must be a little rusty - I've mostly been grading papers, not looking at schematics, this past year. My bad. I certainly see why you thought I wasn't myself based on such a dopey co...

he choke is not at AC ground, the plate of the input tube sees the choke + (1.5K parallel 15K). In this case about 1.4K. Not much different than the free lunch which also has a resistor in series with the choke. I tried a free lunch but had similar sound only worse. That's how it looks to me too. A...

Are you really Jeremy??? The very one and the very same. I was feeling frisky when I first signed onto Dave's new forum so I made up a random username. Hmm. Let's see, how do I prove myself? Well, did you ever see "The Untouchables"? In it, Kevin Costner (as Elliott Ness) tells Sean Conne...

(FYI: Raj Gupta's not-completely-secret identity = Jeremy Epstein) The part that gives me pause is the voltage divider with the bypass cap across it - my question is, does this really work as a bypassed AC ground? Of course it SHOULD but you don't seem to be happy with the sound using that connectio...

re: your last drawing, tha amp you didn't like so well: I haven't seen that particular direct coupling scheme before (the bootstrapped grid of the 71A becoming the B+ of the 1st stage.) Are you sure it works in general? I'm wondering what the output impedance of the 1st stage/input impedance of the ...

Then came the SNAP where i inadvertantly shorted the output cap and it suddenly behaved similarly to the other. If i had to guess, the large DC current pulse form the temporary short put a huge DC force on the core seating it tightly together. That's pretty interesting. I bet you'll try that trick ...

I think one way good broadcast equipment sums to mono is a 1:1:x transformer, with l and r each getting one of the 1's and taking the summed output signal from the x winding. The other way is some variation of a mixer setup.

-j

Any idea why all other threads show up as normal width on my screen (1024 x 768) but this one is too wide and has a horizontal scroll bar?

When there is a photo posted in the thread the whole page of posts takes the width of the photo.

-j

For mono, I prefer using the 841 A2 amp (did you hear that one?) I think I heard the Original Flavor only, with the extremely inexpensive tubes. It's clear to me that summing the channels of a mono source sounds better than leaving them separate. But some people like to have the effect where the mu...

Steve:

What do you generally prefer to do with mono LPs? Do you take the two stereo cartridge feeds and sum them, take one feed and wye it to both channels, listen to one speaker by itself?

-j

380 watts!!

sssssss....sound of balloon deflating....ssssssss

oops.

-j

if one were a cheapskate A pretty big "if," wouldn't you say? Not that I would ever consider such a thing, but a 6V toroid would give you a 3200:8 impedance ratio if one were so inclined, pretty much the balls for loading a 2A3. I think I even have a few of those lying around here. . . wh...

Dave: do you wind these on a smaller core than you would a typical two-winding 2A3 OPT? Or do you just get more LF headroom, on the same sized core? Also: running the 2A3 at 60ma and the filaments at the 42ma cancel winding will net 18ma total DC on the core and the graph for +18ma looks pretty good...

I think it would look like this.

Each pair of outputs would feed a summing bus which would have to be buffered somehow so as not to load or couple to the opposite channel.

-j