Drip Dual-STA 5167 Limiter

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Wow- got so excited I lost all reason and accountability. The shame...

First question still stands! Anyone built it?
 
I have the PCBs (super slick) and most components ready for soldering, waiting to get the case and front panel built. Will be happy to provide progress pics as I go along.
 
This looks interesting, build pics would be cool Bramk, where are you sourcing the case from Bramk?

Think I’d be more interested in the U73b at the moment
 
Ok so i built this one successfully guys.

Although Greg has provided full info on BOM and also Errata updates and its fairly easy to follow his guide

I got stuck in some places and figured out the solution to these issues myself.

This is my first Drip build from scratch, and before this I have only built kits.

Points to Note:

1) Its compulsory;sary to make the changes to the Power Supply as updated in the documents by Greg, else 2 channels won't work and the power supply will start smoking.., after applying the changes,, everything worked perfectly

2) For the VU meters please note the VU is the connection in which i used an sma cable fro the main board and cut it up , so i could attach regular wires to connect to the VU signal part, If you connect sma to sma for VU between the main board and control board, the control board does not work the VU meter, there is some issue with that. So just directly hook up the SMA are on main board to the VU meter directly.

3) The VU meter lamp is lit up by the LAMP SMA connectors , what i did is that i connected LAMP from MAIn BOARd to LAMP on Front panel Control Boards and then soldered 2 cables at the IDC box area ( i did not use an IDC header box over there) .
I made a parallel connection from this LAMP connection to my POWER ON light, as both need 6.3V, it worked!!

4) In the (original SIMPSONS)  VU meter the top 2 terminals are the LAMP power terminals and bottom ones are for gain reduction meter.

5) There Release times go from "FAST" (on left most position ) to  SLOW (right most ) moving clockwise.
    My Case manufacturer made a mistake labelled these opposite , so i had to modify the resistors on the control boards by  changing their order from ascending to descending .


Here are some pics!









anger poems by famous poets


Enjoy!
 
Old thread but this seemed like the best place to post.

Currently building this Dual Sta Level by drip.

It has a revised board and i'm stuck on the PSU because of my lack of knowledge on it. The eratta's Greg posted are for the older board and are for using a solid-state PSU for two channels.

Does anyone with experience and perhaps someone who has already built this be able to explain to me how to fill out the PSU to use the 5AR4 for two channels? (I'm actually going to use a 5y3 I already have.


Thank you,
Ryan
 

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FarisElek said:
Old thread but this seemed like the best place to post.

Currently building this Dual Sta Level by drip.

It has a revised board and i'm stuck on the PSU because of my lack of knowledge on it. The eratta's Greg posted are for the older board and are for using a solid-state PSU for two channels.

Does anyone with experience and perhaps someone who has already built this be able to explain to me how to fill out the PSU to use the 5AR4 for two channels? (I'm actually going to use a 5y3 I already have.


Thank you,
Ryan

Did he revise the PSU for this recently or something?  I thought that all of his recent boards (U73b, Dual STA, Opto 7, Ultra British) use his “universal” psu, and that the Dual STA requires using diodes in place of the tube in order to avoid overheating problems.  The Drip psu board is designed to do either or, but in this case the diodes seem to be compulsory.
 
I assume it works because in a recent email he said,

“the rectifier tube works fine - however you should have a choke to protect it from the big 100uf capacitors i like the hammond 4uf@200ma

or a 5 watt - 10 w 100 ohm resistor in no choke .

or using ohms law : each channel uses 80 ma  so a total of 160 mA in stereo

meh the ohms law calculator says  : a 100 ohm resistor with 160ma only needs to be 3w  .

regards
gregory”
 
Huh, well that’s interesting news!  I haven’t actually started this build yet, as I’m well behind on my collection of projects (and I’m still on the learning curve, so I move slowly), but I’ll definitely be revisiting this when I do.
 
FarisElek said:
It has a revised board and i'm stuck on the PSU because of my lack of knowledge on it.

Good that you are taking a step back... Looks like a biggun...

FarisElek said:
The eratta's Greg posted are for the older board and are for using a solid-state PSU for two channels

Not experienced with this .......

Looking at one errata I found, it's speaking of bypassing the high voltage regulation to cut down on the heat and recommends solid state rectification to cut down on transformer stress from having to supply the tube diode heater. But does give options for either....

Looking at your picture, it looks like you may be following the bypass of the high voltage regulation section although it's not correct from what I can tell as you still have some components in place that should be removed....But idk if you're trying to go for the regulation or not at this point....

Is it recommended to use a 5Y3 in for the 5AR4 in this supply??...I'm not versed in the characteristics of these and how certain parts of the circuit may be affected by changing these two although I've seen it done.....

FarisElek said:
or a 5 watt - 10 w 100 ohm resistor in no choke .

did he say where this resistor is supposed to be at on your board revision?? The older one looks like it has a place marked for it.... I don't see one in your pic...... Are you using a choke?


any reason you are using the tube rectification aside from solid state??

What power transformer are you using??
 
"Looking at your picture, it looks like you may be following the bypass of the high voltage regulation section although it's not correct from what I can tell as you still have some components in place that should be removed....But idk if you're trying to go for the regulation or not at this point...."

This is true. At first I just started filling stuff in and then I read the eratta. There is only 6 components I need to remove. I'm not too worried about it.

"Is it recommended to use a 5Y3 in for the 5AR4 in this supply??...I'm not versed in the characteristics of these and how certain parts of the circuit may be affected by changing these two although I've seen it done....."

I guess they're more or less interchangeable. The 5y3 is known to have a little more "sag". I have to double check the voltages, but I think they're about the same.


"did he say where this resistor is supposed to be at on your board revision?? The older one looks like it has a place marked for it.... I don't see one in your pic...... Are you using a choke?"

He didn't...I asked but his answer didn't really make sense. He may have thought that I had the older board. I'm not sure. I want to use a choke but I don't know what choke he's referring to. I haven't seen any with a faraday rating...? I don't know much about chokes.

"any reason you are using the tube rectification aside from solid state??"

Honestly just because a member here with more experience than myself told me that the tube circuit does something great to the sound that he believes would be worth it to me, as I'm looking for as much color as I can get from the unit. I'm thinking of just building the solid state circuit with a choke though a I really don't like to be confused about PSU's...especially tube ones.

"What power transformer are you using??"

Hammond 272HX. Although the eratta recommends the 270HX which has 550V  instead of 600. Might change to it the 270 as I haven't opened it yet and I'm assuming it's for the solid-state psu circuit.


Ryan
 
I feel super annoying, but I clearly wrote out all my biggest questions and sent them to Gregory. He seems very cool about it and said he'd get back to me tomorrow. Once I get this figured out, I'll post Gregory's explanation and some pictures here. Maybe it will help the next builder.

Ryan
 
That would be cool... You should invite him here...Wasn't he active before??

Anyhow, looking again at the errata real quick I see that the (2) 1k resistors are supposed to be 33R 3watters along with the additional one that had a spot on the old board for use without a choke....Maybe he's saying to make these (2) equal 100ohms....

Be kinda weird to throw a 33R on the terminal strip or maybe even that diode spot that is jumped in lieu of the choke since the old board had a place...but who knows....

Please do update....

Yeah he probably didn't mean to give the choke in farads....
 
I’ll definitely let you know.

In the meantime. I was curious about the input transformer. I’m using the Lundahl LL1922 because I had easy access to some in the states. I was originally going to do the Sowter, but it was going to end up costing more than I’d like.

Anyway, with the Lundahl there is an option for using 1:4 ratio or 1:8 ratio. I’m a novice when it comes to audio transformers. What’s the difference? Is there one more preferable than the other?

Also meters. Obviously I'd prefer the Simpson meter that show -40db of gain reduction, but they're extremely expensive. I've got some gorgeous vintage VU's that look perfect but only go to -20. Will it work?
 
I have some questions about this build. Gregory was being really good at getting back to me about getting back to me but never did so I'm going to attempt to find out some of these questions here as he seems really busy.

1) The XLR PCB  has holes for underneath the relays for Diodes. I believe they all say "D9". Are these alternatives to the Relays? I ask because there is no mention of them in the build information and they weren't any extra diodes in the BOM. They're also not labeled as to which diodes they were referring to. Since I'm pretty sure these are universal XLR PCB's, i'm thinking it's for a different build and that I just use relays in this one. I may be very wrong as I'm pretty sure I've used relays along with diodes in other builds.

2) There is no information for set up once everything is wired. How do I calibrate all the voltages and trimmers correctly? Will that not work because I need the load? Which trimmers do what? Some of them are obvious but others I'm not exactly sure.

3) On some builds as well as the collective case panels there is an area for the meter zero adjust. There is no information of this on the build, how do I instal it? what kind of pot should I use?

4) Is there any affordable meters for this build that are shaped like the Simpson model 47 but not $200 a pop? I have some old vintage meters lying around I can use but I just noticed today that the lamp is potted in some clay and the bulbs are dead so I can't use the whole lamp mechanism without jerry-rigging some LED into it, on top of that the GR isn't right and I'd rather just get a new one.

5) The lamp/6.3v seems shorted to ground even on the SMA connector despite if I cut pin 15. What's that about? The main PCB itself seems to have shorted to ground somewhere. It seems like it's because the IDC header pins for ground and 6.3v are connected. But even if I cut pin 15 on the control board there is continuity. Is it because the electricity flows one way and I don't have to worry about continuity? Also, my high voltage 600v transformer wires have continuity with ground on the PSU pcb too. Is this another thing that's okay because the diodes move the current away despite being connected to ground?



I'm awaiting the output iron but besides that I'm completely that and what I mentioned above, I'm completely done. I'm really nervous about it because I've never built anything quite like this + the lack of build info.


Thank you,
Ryan


EDIT: I'm adding to this post my image for the Simpson 27 Meter. You can take a 200ma Simpson 27 meter, print this paper out, and stick it to the backplate of the meter. It should print out the right size.

 

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So the main thing I want to figure out is why there is such a small resistance between ground and 6.3v. I initially thought it was continuity, but it's actually about 1.5ohms. Is that okay? It says everywhere on the build to make sure 6.3v isn't grounded, but it actually has some resistance. Is this safe?


Ryan
 

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