iprovlek

Re: HE-569 pre/eq 500 series
« Reply #20 on: June 19, 2019, 07:21:43 AM »
Great work Paolo!

Is there progress on it!?


pahstah

Re: HE-569 pre/eq 500 series
« Reply #21 on: June 19, 2019, 12:35:45 PM »
Great work Paolo!

Is there progress on it!?

yes, i'm currently finalizing the new pcb.

iprovlek

Re: HE-569 pre/eq 500 series
« Reply #22 on: June 19, 2019, 03:31:49 PM »
Great Paolo!!!

Im for two boards...

OneRoomStudios

Re: HE-569 pre/eq 500 series
« Reply #23 on: July 11, 2019, 11:32:30 AM »
Hi Paolo, any more news? I'm excited to learn more about this project.

pahstah

Re: HE-569 pre/eq 500 series
« Reply #24 on: July 11, 2019, 03:49:53 PM »
keep the faith ...

Re: HE-569 pre/eq 500 series
« Reply #25 on: August 03, 2019, 03:53:51 PM »
I am also in for a pair of these badboys! Please put me on the list!

Re: HE-569 pre/eq 500 series
« Reply #26 on: August 04, 2019, 09:41:53 AM »
This looks great!!! Inspiring work indeed!

pahstah

Re: HE-569 pre/eq 500 series
« Reply #27 on: August 05, 2019, 08:10:00 AM »
I've just sent pub ver 2 to the manufacturer, should be here in few days, then I have to build and test the unit... lot of work for this baby

Ricardus

Re: HE-569 pre/eq 500 series
« Reply #28 on: August 05, 2019, 10:46:51 AM »
AWESOME!
Audio mastering for hire..

boji

Re: HE-569 pre/eq 500 series
« Reply #29 on: August 08, 2019, 10:13:38 AM »
Nice, thanks for update


Re: HE-569 pre/eq 500 series
« Reply #30 on: August 08, 2019, 08:53:44 PM »
Nice work Paulo  :)
I like that you've made the amplifier boards as daughter cards for ease of switching, fixing, building etc.  but not constrained yourself to the usual 990 footprint and sizing enabling you to get more stuff on the cards.
Did you come up with your own format in terms of pin locations etc?  Or is there a standard other than 990/2520?   
I'm working on a similarly sized amp board but can't seem to decide on a standard to stick to.
Anyway, looking good so far fella 👌

Rocinante

Re: HE-569 pre/eq 500 series
« Reply #31 on: August 08, 2019, 10:02:07 PM »
Great to read Paolo. I'm so excited to see this as your work thus far has been very remarkable.
If there's a harder way to do this, I haven't found it yet.

pahstah

Re: HE-569 pre/eq 500 series
« Reply #32 on: August 13, 2019, 04:52:46 AM »
Nice work Paulo  :)
I like that you've made the amplifier boards as daughter cards for ease of switching, fixing, building etc.  but not constrained yourself to the usual 990 footprint and sizing enabling you to get more stuff on the cards.
Did you come up with your own format in terms of pin locations etc?  Or is there a standard other than 990/2520?   
I'm working on a similarly sized amp board but can't seem to decide on a standard to stick to.
Anyway, looking good so far fella 👌

Thank you John,
The format is an idea of mine, nothing really special.
the idea behind the boards is to have the capability to insert them vertically like a 990/2520 footprint but also horizontally into a connector with a 2.54 mm pin space. So if someone is going to use them in a more point to point build like the original modules he has the ability to do it.
it is also practical so i can insert them in a breadboard to run test for them.

Quote
Great to read Paolo. I'm so excited to see this as your work thus far has been very remarkable.

thank you Rocinante!

Re: HE-569 pre/eq 500 series
« Reply #33 on: August 13, 2019, 12:13:57 PM »
Thank you John,
The format is an idea of mine, nothing really special.
the idea behind the boards is to have the capability to insert them vertically like a 990/2520 footprint but also horizontally into a connector with a 2.54 mm pin space. So if someone is going to use them in a more point to point build like the original modules he has the ability to do it.
it is also practical so i can insert them in a breadboard to run test for them.

Great, I like it!  You gave me the push I needed/wanted to just go ahead and do something similar.  Thanks Paulo. 
Marking this thread so's to keep up to date on it 👍

pahstah

Re: HE-569 pre/eq 500 series
« Reply #34 on: September 10, 2019, 08:52:23 AM »
this the second version, with the frontpanel design. there's stillsome adjustment tommake so i will do a thrid version that hope will be the definitive one. the main problem is oscillation above 70 db of gain with the 1:10 tap inserted, no oscilation with the 1:1 tap.





OneRoomStudios

Re: HE-569 pre/eq 500 series
« Reply #35 on: September 10, 2019, 09:57:14 AM »
This looks awesome. Great progress!

iprovlek

Re: HE-569 pre/eq 500 series
« Reply #36 on: September 10, 2019, 10:42:01 AM »
Great Paolo!!!

Hardly waiting for finish version!

Rocinante

Re: HE-569 pre/eq 500 series
« Reply #37 on: September 10, 2019, 09:38:32 PM »
Awesome
If there's a harder way to do this, I haven't found it yet.

Re: HE-569 pre/eq 500 series
« Reply #38 on: September 11, 2019, 03:04:09 PM »
the main problem is oscillation above 70 db of gain with the 1:10 tap inserted, no oscilation with the 1:1 tap.

Can you determine where the oscillation is as regards frequency and particular transistor?

Just in case you haven't tried this, an easy trick in keeping a particular transistor from oscillating is to put a lossy component in two of its three leads.  Either small value resistors or ferrite beads right at the transistor.


TwentyTrees

Re: HE-569 pre/eq 500 series
« Reply #39 on: September 14, 2019, 06:17:36 PM »
Just chipping in to agree with others above - this looks grand, and I really like your v2 faceplate. I find it easier to parse than the 500-series Helios, somehow.

I’m curious as to which direction you went on the gain control in the end - did you use a two gang switch to expand the headroom, or something else? Edit: Just noticed the “Boost” button, is that the trick?

I also note a screw hole in the bottom right corner of the main PCB, are you considering an L-bracket to strengthen the module? With that much iron on it, I guess it may need it!

Great work. Can’t wait to see the finished product.

Andy
« Last Edit: September 15, 2019, 07:06:02 AM by TwentyTrees »


 

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