Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500

[rooster21]

It basically depends on demand.... email me and I will add you to the list.... if the list gets big enough we'll do another limited run.

my ez1073 is lush but feels alone ....so interested in 2 more full sets or 2 partial sets (pcbs+psu/input trannies+inductors+pots....got some marinair output trannies waiting for that project, depending on what kind of kit you would be willing to sell)

I'll arrange to do a limited run of "full" kits as we did before..... Once I have sorted it out, I'll get it back on in the store, but there will probably be a lead time of about 6 weeks.

Colin
www.audiomaintenance.com

I'm in for a second run, never forgave myself for missing the first run.

 

[grubbyliver]

A pair of 1U version pcb's for me please, thanks for offering these again Colin.

Ben

 

[Studio Mollan]

Count me in for 2-4 kits.
Thanks for this!!!!
/
Emil

 

[Studio Mollan]

Hi again,
Is it possible to add a Low pass filter to this design? Like in the 1081.
/
Emil

 

[Slenderchap]

Is it possible to add a Low pass filter to this design? Like in the 1081.

Add some capacitance between your signal and ground.... that will kill the HF.

We should have availability of the 1U version on the 1st November.

Colin
www.audiomaintenance.com

 

[Rellister]

I had some problems with cold solder joints on the bigger capacitators and on the trimmers solder joints.
The solder joints for these parts on the PCB are quit small and Im not sure if its my solder point being to wide. Tried a smaller tip but didnt get much better.
Anybody else had the same problems? Or anybody have some helping ideas?

Hi Colin, love this project, but I also have some annoying problems with the pads. Solder simply refuses to stick to the small ones. Never experienced this before.  Higher tempereature doesnt help. Should I use different solder?

Cheers
Rune

Edit;
I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it

 

[Slenderchap]

I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it

Cool (no pun intended).... Lots of people have made these without problem so didn't think there would be a "PCB" problem..... and we get lots of other PCB's from the same manufacturer.... I would imagine that the most likely place to have issues is when soldering pads which are part of the ground plane.... there are thermal spokes on those pads but it can still be a little tricky if the iron is not hot enough..... using leaded solder will make it easier.

Colin
www.audiomaintenance.com

 

[Studio Mollan]

Hi Colin and thanks for your reply.
Where's the Best place tp put this filter? I've heard it will start messign upp the high pass if placed directly after/before it. Just after the second stage?
/
Emil

Is it possible to add a Low pass filter to this design? Like in the 1081.

Add some capacitance between your signal and ground.... that will kill the HF.

We should have availability of the 1U version on the 1st November.

Colin
www.audiomaintenance.com

 

[Slenderchap]

Where's the Best place tp put this filter? I've heard it will start messign upp the high pass if placed directly after/before it. Just after the second stage?

Just experiment and see what results you get ! .... you could start by altering the zobel network on the output transformer.... after all it is just a low pass filter !

Colin
www.audiomaintenance.com

 

[manulaudic]

How much does the 1U pcb runs for? Do you have any more to sell?

also, what's the approximate price for building the whole thing, if anyone can give about... would be great

Cheers,
Manu

 

[mulletchuck]

Here in the states, all of the parts including case from ddt and cheap RadioShack knobs ran roughly $800.  here's what my breakdown was:

$570 preamp kit (355 British Pounds)
$128 Case (96 Euros)
$2    Power Entry Module/w fuse holder
$2    fuse
$3    PCB standoffs
$3    PCB Standoff Screws
$2    Wiring
$15  XLRs
$65  9 front-panel Knobs.  <-- fancy knobs from Cathedral Pipes

I ended up going with Radio Shack knobs that cost about $6 for 9 of them.

 

[manulaudic]

Thanks mulletchuck

That gives a perfect answer. Though still don't know the price of the PCB and if it's still available. Anyone?

I got the Golden Age Pre-72 MKII for 300 euros, and it's quite nice, it's not a kit and a cheap copy using cheap transformers but has a nice built quality and good sounding if not driven too much. then it gets noisy...

Is it possible to turn that 1073 into a 1272? because i don't think anyone needs 80 db of gain...

Manu

 

[Slenderchap]

Though still don't know the price of the PCB and if it's still available.

The PCB will not be available seperately.... it will only be a limited number of kits of the 1U version ... 1st November.

Colin
www.audiomaintenance.com

 

[manulaudic]

I see,

and what's the price for that kit?

manu

 

[Slenderchap]

and what's the price for that kit?

Probably GBP 365.00.... Depends on how much it costs to do the kitting.... I'm not doing it again, it's a mercy-less task.... I am paying someone else to do it.....

Colin
www.audiomaintenance.com

 

[grubbyliver]

The PCB will not be available seperately....

I'll have to dip out in this case, can't spring for full kits right now sorry.
Some other time perhaps...

Cheers
Ben

 

[Rellister]

it's a mercy-less task....

I can imagine. The BOM contains all part numbers for "special" parts, and you also have the AE caps in stock.
The partial kit was fine with me...but I cant´t speak for everyone.

 

[Slenderchap]

I can imagine. The BOM contains all part numbers for "special" parts, and you also have the AE caps in stock.
The partial kit was fine with me...but I cant´t speak for everyone.

The kits contain all the parts that go on the PCB.... 134 different items.... 396 items in total....  takes a couple of hours

They are now back in stock.

Colin
www.audiomaintenance.com

 

[Rellister]

Hi,

My EZ1073 works fine, apart from a small hum when the eq is engaged. It gets stronger when selecting mid freqs, 360 and 700Hz in particular. When turning the eq off its quiet. At line level its somehow worse, present at a small level even without eq engaged. Could it just be toroid related? Could try moving the toroid off board. Also tried removing ground at xlr input/output, removing toroid ground and "mains safety earth" with no luck. Any suggestions from people familiar with this circuit? What I´m trying to find out if this is just a "normal" toroid hum or something not being earthed properly, maybe in the opamp A+B circuits.

Thanks!

 

[mulletchuck]

these builds are dead silent, so something got messed up.  double and triple check all your solder joints and wiring.