EQN build thread

[dmp]

I believe what you have circled as 2 is for a three pin header. If I recall correctly it terminates the output transformer with R37 if a jumper is installed (600 ohms). Look at the traces to see if this makes sense.

 

[canidoit]

Is there info on how to calibrate this build? I have read zayance post but do not understand what he is talking about?

What is the most cost effective way of building a test rig for my 500 series builds?

Can I buy a 16 volt laptop charger and use that for power?

Where do I get those blue API socket that is in my lunchbox and what part number are they so I know what to buy?

How should I wire the tab at the back of this build to test it out of the API lunchbox?

Thank you

 

[JBVries]

Jeff @ classicapi.com has the sockets.

I think you could just build a power supply like the ones APP makes (http://www.groupdiy.com/index.php?topic=33576.0) and be on your way.

(somebody please correct me if I'm wrong.)

I'm not trying to bust your chops, but try to spend some time SEARCHING around the forum and you will find most everything you are looking for. Use "parenthesis" to search for exact text "51x socket" or whatever and only select rooms that would be applicable (IE: The lab, Drawing board, maybe the markets).

 

[mikefatom]

Get the edge connector from Jeff, Cemal or Volker.  Make sure you get the 51X connector which has 36 connectors.  You will be able to use it for your 500 builds as well as your 51X builds!

Build yourself a simple connection kit like I've done here:
http://www.groupdiy.com/index.php?topic=41312.msg518780#msg518780

Good luck,

Mike

 

[canidoit]

Thanks 

Peter, any reason why you did not use a linear regulator instead of a DC-DC converter for this build? I have read that it jeopardizes the quality of audio in the unit.

Also what is the calibration procedure for these units, I have searched and can not find any proper information.

 

[peter purpose]

Ask Colin why he does, not why I didn't.
Adjust rv5 for symetrical clipping.

 

[JBVries]

Peter,

Am I to gather there could be a better part in my EQNs than is currently? If so, could you recommend a linear reg that would be compatible?

 

[haima]

JBVries - i think both Peter and Colin have chosen different ways to skin the "+/-16v-to-24v" cat - they both have their reasons for choosing the path they have taken... neither are wrong.

Is there something in particular you are unhappy about with the sound of your EQNs? Mine sound awesome. No noise or other issues.

There are hundreds (thousands?) of satisfied users of the Great River 500 series preamps, onlymee N73 preamps & EQN eqs - all these modules use the same TDK DC-DC converter and surrounding circuitry AFAIK (unless you are using the 51X pins on the latter two).

You can't easily drop in a linear regulator in place of a DC-DC converter - it would require some modifications to the circuit and board - if i was you i'd keep you EQNs stock and enjoy them, unless there is an actual problem that needs fixing.

BUT this is DIY so you can do what you want - Just don't expect Pete to help you redesign his EQ.... i imagine he's got better things to do.

 

[JBVries]

Thanks Haima,

As an admitted novice and also a so called "Muso" (musician in a rush for best musical quality) ;D I didn't mean to offend or imply that anything was lacking and please don't take my ignorance as such. Still have yet to do the final power up but I just wanted to make sure that everything was the way it should be as I know builds can change and Mods happen.

Cheers and thanks for the reply.

Pete - please go ahead an disregard that question.

 

[haima]

No probs - I too have wondered about the DC-DC converter... and if there's another way - but in practice they work well in this application.

AFAIK there is no errata for this build - it all works as intended 

Finish off your EQNs and i'm sure you'll enjoy them - i've been using my pair extensively. Love them!

 

[crisotop]

I bought my kit in the blackmarket and am missing the heatsink - anything special about it (besides that it should fit the board)?

thanks!
christoph

 

[JBVries]

Nope, it is definitely more robust than your run of the mill V reg heatsink but aside from that no apparent differences.

 

[crisotop]

Thanks - that's why I'm asking, don't know if I should look for specific dissipation values, because it looks much thicker than the heatsinks I've got at home.

 

[peter purpose]

If you want the right thing.... Farnell 1703179

 

[crisotop]

wicked - thanks peter!

 

[crisotop]

my pair is finally up and running - thanks for the easy layout / build. Are you guys using any altered termination on the output trafo? My frequency response is a bit "off" at the very low and high end (~3dB down). As far as I can make out R37 is the 600 Ohm load - is C61 (C62) parallel to R37?

Thanks!
Christoph

 

[peter purpose]

As far as I can make out R37 is the 600 Ohm load - is C61 (C62) parallel to R37?

R37 is the load.
No... c61 c62 are not parallel to r37.

3dB down at what frqs?

 

[crisotop]

just measured again, with a more precise method. It's not as drastic anymore. 1.5dB down at 20K, unity gain from 7k down to 900, then back to 1.5dB down at 20Hz. Not that I worry much, but my other "Nevish" builds have quite the noticable frequency bump in the very lows and highs, that's why I'm wondering.

Thanks for the support Peter!
Christoph

 

[canidoit]

Pete,

How much current does this build take.

 

[peter purpose]

Pete,

How much current does this build take.

Within specification.