[NXSTUDIO-DRUMMER]

Douk Audio A5 is a welcomed product in the household.




Example of what not to do, mounting expensive Staccato op amps in a A5.

[NIGHTFALL1970]

I also purchased a 10 amp power brick and it makes a night and day difference! Symbol crashes sound a lot more life like. I haven’t played around with different opamps yet but,  I bet the power brick has the same difference in quality.

[Jon L]

Who did this and aside from how it looks, did the opamps work kinked like this?  I'd rather use the standard extender and bend the pins than use the super-long wire extenders.

[NXSTUDIO-DRUMMER]

Who did this and aside from how it looks, did the op amps work kinked like this?  I'd rather use the standard extender and bend the pins than use the super-long wire extenders.

Jakub from Staccato sent me that photo, of a another customer attempting to install.

 

[Jon L]

IF I were to get Staccato, I would just use two extenders on one side. 

But I'm trying to refrain from buying any more discrete opamps, including the interesting-looking Virtual Hifi opamps:
https://www.youtube.com/watch?v=Mub-xo619PY&lc=UgxdVC0dgL6KaUa1-qN4AaABAg.AKBzsVzeGuyAKIDM8Gt2Ms

[nlitworld]

Has anyone measured the input impedance of this little guy? Curiosity got the best of me and I just ordered on prime day deal. $95 with the 48v power supply is too tempting. Asking on impedance since I usually run a high pass filter on my preamp output.

[tremrej65]

Has anyone measured the input impedance of this little guy? Curiosity got the best of me and I just ordered on prime day deal. $95 with the 48v power supply is too tempting. Asking on impedance since I usually run a high pass filter on my preamp output.

There's an integrated adjustable high pass filter in that box (the left knob). You most likely don't need an external one.

[nlitworld]

Yeah but typical audiophile neurosis says the capacitors in there to facilitate an adjustable high pass are not very quality compared to the Miflex and Duelund I'm used to hearing. We're guilty of falling down our own rabbit holes in this hobby.  I'll figure out tomorrow when I get it and can report back.

[NXSTUDIO-DRUMMER]

Yeah but typical audiophile neurosis says the capacitors in there to facilitate an adjustable high pass are not very quality compared to the Miflex and Duelund I'm used to hearing. We're guilty of falling down our own rabbit holes in this hobby.  I'll figure out tomorrow when I get it and can report back.

Hey Lloyd, I wondered about it too.

[NIGHTFALL1970]

We are all crazy here (so I feel at home) and I thought about adding Danny’s Tube Connectors, but I don’t think there’s room.

[nlitworld]

Yep, I figured at such a cheap entry point, getting wild with a soldering iron on there sounded like fun. RCA jack, speaker post, opamps, etc. Worth it given the cost of the unit, surely not. Fun project for a weekend of tinkering, heck yes. Thanks for the internals photo. Wheels turning for possibilities.

[NXSTUDIO-DRUMMER]

IF I were to get Staccato, I would just use two extenders on one side. 

But I'm trying to refrain from buying any more discrete opamps, including the interesting-looking Virtual Hifi opamps:
https://www.youtube.com/watch?v=Mub-xo619PY&lc=UgxdVC0dgL6KaUa1-qN4AaABAg.AKBzsVzeGuyAKIDM8Gt2Ms

Here is another manufacture John L shared, Thanks John! 
https://virtualhifi.com/products/supersonic-v1-op-amp

[Jon L]

I really love what Virtual Hifi is doing with Qualio line of speakers, and these opamps do look very interesting.  However!  Make sure your equipment can handle the extra heat and current requirement of Virtual Hifi opamps 

[nlitworld]

First listen in straight stock form, pleasantly surprised, even without subs. Will let it break in then start to mod in a couple weeks. I really don't need another project, but this will be fun.

Also, input impedance is 7,900 if anyone is wondering. That'd make a 0.22uf cap roughly about 90hz xo. Probably have one of those laying around. 

[NXSTUDIO-DRUMMER]

Good information to know Llyod, thanks for advising us all.

John L, your point well taken.

[NXSTUDIO-DRUMMER]

I've heard and read favorable reviews on a SX52B OP-Amp.

[nlitworld]

Sparkos ordered, as well as some Nichicon KZ caps for the coupling caps in the middle there. I already have some extra KLE rca jacks to replace those cheap ones and I'll try to figure out a way to mount some tube connectors off the back. Should be a fun little mod project.

And to think I only investigated these as a summertime hot weather amp alternative to tubes.

[NIGHTFALL1970]

Nlitworld,
Please post pics and step by step instructions if you add tube connectors.

[NXSTUDIO-DRUMMER]

Some good information regarding op amps.
https://www.youtube.com/watch?v=kNDX7SCN6Jc

[nlitworld]

So I did mess around with the high-pass knob this morning. There is a good chop of low frequencies going from off to 50hz area, but the a big stretch of no-man's-land where it will drop a tiny bit but no fine adjustments. Then just on a whim I maxed it to full "200hz" and turned up my Rythmik F8 to 150ish. Oh man that's good. These subs play so well up higher and the little amp sounds much more nimble and open. Not half bad right now, and it's still bone stock. I'll probably investigate higher filter levels since I have some 0.15uf Miflex in the garage which would make for 137hz filter, or even a 0.1uf which would be 200hz.

As to my thought on mounting tube connectors, I was essentially planning to glue a standoff acrylic block in the back that the tube connectors could sit in, Probably add a footer so the balance doesn't cause it to tip over while I'm at it. Should be easy enough and I have 2part adhesives in the garage.