Fester's TG12413 in 51X format.... TG51X? Getting closer.........

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http://www.groupdiy.com/index.php?topic=37400.msg622710#msg622710

Porn stuff coming.......
 
Output trafo, ELMA switches, meter and knobs are not included.

Many tastes - many choices, so...
I prefer it clean; others may prefer "dirty" iron and slammed low-end.....

ELMA's and meters - you don't have to pay shipping back and forth to Israel and Israeli VAT.
Buy it yourself and safe some bucks.

Hairball meters for SSL mixbuzz and Sifam 1mA FSD will work, there is a shunt circuit with pot to adjust full scale.

For the people who don't need precision steps and can live with potentiometers,
the info about changing the input/output ELMA switches to pots will be posted soon.

In any case, I recommend to stare 10 minutes into documentation

http://ij-audio.com/downloads/TG1_51X_DOCUMENTATION_prelim.rar

and meditate a little bit. Detailed pictures are inside.
Just switch off the brain and get whole idea about this build.
IMO nothing special, I tried to keep it friendly as possible.
 
Cool than. Due to local holidays, some packages with parts delayed, but already here, in Israel.
I love custom's like a possibility of atomic war. Meanwhile, most of kits stuff arranged.

Important thingy.

I got this question regarding 2RU version of TG. However, useful here as well.

I read that a 2.4mA meter is required but is there any chanche of using an easy availably 1mA sifam meter?

Yep, easy. Just an adjustable shunt - take about 22r resistor connected in series with 200r multiturn trimpot;
than connect them in parallel to your meter.

Feed some voltage thru appropriate variable resistor (for 5V, the 2.4mA current will be at 2.083 Kohm);
monitor the current with milliampermeter (Fluke at 20mA range) and adjust the shunt for FSD (full scale deflection, 100%)
when the current is exactly 2.4 mA. For this purpose, 2k083 resistor (may bit vary due to total resistance of shunt and meter)
done from 1k5 resistor and 2k potentiometer, connected in-series.
Adjust 2.4 ma - adjust FSD - readjust 2.4ma - readjust FSD - done.

I will post exact pictures how to do it right with potentiometer located at PCB. Takes 5 minutes to set and forget.
 

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Hi Igor! How are you? No news good news??
My impatience is as strong as my gratitude!!! :)
Can't wait to build and taste this great project.
Cheers.  Marc
 
 
I don't know if this would be better suited in 'project specific', but figured we could use this now to aggregate build info.
I couldn't quite figure out how the resistors and caps were bundled, so i ended up just going through and repackaging them for what i need. There are a couple of errors on the boards that i have found. The 2n4998 and 2n4910 have the base and emitter backwards(assuming the '1' and '2' reference to the datasheet'. They install correctly, the other way doesn't fit, so it may have already been a non issue, but just for reference.
Also, C17 is right on the silkscreen, but wrong on the layout sheet.
-The diodes are unmarked, but the black diodes are the 4148's. The bigger orange diode is the 5.1 zener. My '2051's' were marked as '4.7' and '5.3'. I am assuming this is saying they measured between the 2. In any case, i went ahead and soldered them in as is, without making a test jig.
-I had a number of wrong/missing components. On many of the electrolytic caps the values were pretty off. I don't think i had any 330u for example, but had some 150u in the kit. but i had some laying around. Also, the voltages were lower on some of the caps(16v, instead of the 35-50v on the BOM). No 33p that i could find, and a few missing resistors. VT25 and 26, came with bc109 and bc179. Those parts are direct subs for the bc107 and bc 179. TL431CLP are right for VR1 and VR2.
I saw a couple of people asking how the switches would line up with PC for the in and out. It has been so long since i ordered the kit, but i found info saying that the switches, as well as meter, and trafo, don't come with the kit.
-the one thing that is confusing to me is the 2 separate pcbs's that both have recover and hold. The smaller one doesn't line up with the frontplate. I am assuming it is to make it with the original circuit? But i want to make sure. The information is so scattered, and the schematics are all modular, so its kind of hard to figure out what is going on.
I have populated most of the components on the 2 main boards. Waiting on a transformer, and looking into meter options. Also, where are you guys getting your 21 position switches, and meters?
Anybody else making any progress?
Ian
 
I am going with the 3.9k for r19(relay voltage), as it seems that it was determined for these general values. I am also using the LL1524, so will be using 10nF and 1.5k for my zobel to start
 
I have the 10k trimmers with top adjust that came with the kit. It looks like we probably want side adjust, as the top adjust would not be adjustable once the other board is set into the switch board
 
Wondering if 2n4898 and 2n4910 need to be insulated? Saw that on the the other build thread.
also trying to find some meters that can work. I have some old VU's that fir perfectly, but looks like it needs to be 2.4mA FSD. What is the easiest way to make a VU work in this capacity?
 
since the schematics are modular, i thought i would bridge a couple of gaps:
The 4 position "iptr" goes to the bypass switch on the faceplate. -found out that this is for the optional input transformer

you can reference to the "audio schematic" and see there is "iptr3" and iptr4" going into the input ic, ina134p. after that is C5a, and then "iptr1" and "iptr2", which connect to the input attenuator.
-i think the input attenuator is at the same place. You can see it on the audio pcb "inp" right next to C5. It isn't clearly marked, but looks like "inp1" goes to the top of the switch, which would be at position 22, 1087r, "inp3" would go to position 1 on the switch, which is the ground reference. The wiper of the switch goes to "inp2" which goes into r78 and into the audiocircuit.
-the output attenuator is taken after C99. "out1 goes to the top of the output attenuator, which is easiest seen on the original TG1 schematic, called "sharpened fixed". you will connect "out1" to position 22, which is the top of the 3.3k. "out3" will be to position 1 on the switch, which is also a 3.3k. "out2" connects to the wiper
 
Amendment:
On further review, it seems that the bypass pcb has only the 2 pads, which come from the top of the main pcb. There are also pads to connect to the LED, but i am thinking that may be for the other(simple board), as i am assuming the switch connects the +Ub and -UB this lighting the LED on the PCB.
I'm now confused as to what the 4 position 'ptr' is for. It is obviously to connect the relay/bypass circuit to the input, but it seems that the bypass switch accomplishes this as well.
I also put together the input attenuator that goes right after INA134p. The resistors were not supplied with the kit, but i had enough laying around to make it work. I see that Igor's front panel has both input and hold, which is confusing as i thought it was an either or. I guess using the attenuator at the top of the circuit would work interactively with the hold further downstream
I am trying to figure out the shorthand used in the schematics. I think FP is for the 2 front panel pcbs. Looking at the schematics, i can't see where the "audio schematic" connects to the front panel. I can cross reference to the original tonight, but need to get back to it later
 
I had some structural questions first of all. Trying to put all of the boards together is pretty confusing without a bit of a diagram. I think i have it figured out but had posed a few questions earlier in the thread largely for the builds following mine.
There are a few discrepancies. The hardware is not correct. I am missing some standoffs.
Also, the zeners that are supposed to be matched came in a small ball of foil with 4.7 and 5.1. I am assuming either there are 2 matched pairs or that they vary from 4.7-5.1v, which is a wider tolerance than we are supposed to have.
It is a pretty expensive project to buy with no support at all. The docs are self described "temporary" docs, and there was a promised build guide now months ago. I mainly feel stupid for allowing myself to be duped.
I will try to finish it
 
The ELMA switches were not included, as stated. However, the circuit boards do not accomodate ELMA switches, so I'm not sure how to incorporate them. The small circuit boards in his "preliminary docs" showed small boards where you could mount the ELMA switches. Those were not included in my kit so I'm not sure how they'd be hooked up.
 

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