All things G1176 - the new "repost" thread.
- Thread starter orson whitfield
- Start date
Help Support GroupDIY Audio Forum:
:thumb: Amazing! It worked at the first shot! I simply powered up the 1176 and it worked without problems at all! Last weekend I went to play with my band so I committed a friend of mine to check the first part of my work: the proper resistences values, caps and diodes polarity. Then I followed mnats advice and went ahead only with the power section first. The tensions were ok. I finished the boards with the rest of transistors and IC's then I made all the wires connections, mostly with shielded cables. I powered up and.. That's all! I started last year a small business named "RealTone" building vintage guitar stomp boxes clones and now I am glad to add this product too to the list. Later, I will fill my studio rack with four 1176 at least! Visit www.studiotriton.com Text is in italian (I live in Italy) but pics and gearlist are clear enough! Thanks to Mnats and Gyraf and bye bye to all of you.
skrasms
Well-known member
Alright, I've been over the Mnats PC board more times than I can count now, and I just can't find where "R1 - 150ohms" goes. His site says R*1 is an optional 10k, so I thought that wouldn't be the spot for it... unless the 10k is optional in place of the 150ohms. I'm sure this is something really simple, but I'm not seeing it.
The simple answer is the PCB software I used freaks out if you don't start your component numbering with "1". I used the numbering from the schematic which starts the resistor numbering with "R1A". So it seems that it generated plain old R1 on its own and even gave it a value when it spat out the bill of materials.
Funny that no one noticed until now. It's been updated on the BOM on my site. Thanks for finding the error.
Funny that no one noticed until now. It's been updated on the BOM on my site. Thanks for finding the error.
skrasms
Well-known member
Glad to know I'm not just crazy!
Whoa, SeStesso - is that an Altec 1176? :razz:
Surely looks good! :thumb:
Jakob E.
Surely looks good! :thumb:
Jakob E.
hi to all! i've searched this board for hours, but didn't exactly get the answers
i hoped to find. first, i've build the 1176 in mnats version with an input transformer. when i measure the the voltages and compare with gyraf's voltages, they match very well. so the board itself should be ok.
when i connect an signal at the input, i get the same signal at the output. also when the unit is switched off. is this normal?
the GR is obviously not in use. the meter does not move and the input gain and output gain pots don't to change anything. i know that i must connect the pot input to *1, but to the remaining pins of the pot still go to pins 2 and 3 on the board??
hope you can help me!!
i hoped to find. first, i've build the 1176 in mnats version with an input transformer. when i measure the the voltages and compare with gyraf's voltages, they match very well. so the board itself should be ok.
when i connect an signal at the input, i get the same signal at the output. also when the unit is switched off. is this normal?
the GR is obviously not in use. the meter does not move and the input gain and output gain pots don't to change anything. i know that i must connect the pot input to *1, but to the remaining pins of the pot still go to pins 2 and 3 on the board??
hope you can help me!!
Definitely not.
Read the schematic and compare with the board - that should make it clear how to wire the unit..
Jakob E.
matta
Well-known member
Hi Guys,
For the 2 BC560's is there an optimal/mini Hfe? I have some 560C's, which read out around the 450+. Will these be okay? The Schemo says that the BC107's in places need to be above 250, but doesn't mention the BC560's.
Also for the record when a part just has a number and no A,B, or C, what is the Hfe? Is it higer than C or lower than A or equal to C?
Thanks
Matt
For the 2 BC560's is there an optimal/mini Hfe? I have some 560C's, which read out around the 450+. Will these be okay? The Schemo says that the BC107's in places need to be above 250, but doesn't mention the BC560's.
Also for the record when a part just has a number and no A,B, or C, what is the Hfe? Is it higer than C or lower than A or equal to C?
Thanks
Matt
Hi Matt,
Any BC560 will do fine here - that's why they're not further specified.
For further info on transistor specs, simply look up the manufacturer data sheets..
Jakob E.
Any BC560 will do fine here - that's why they're not further specified.
For further info on transistor specs, simply look up the manufacturer data sheets..
Jakob E.
mfdu
Well-known member
i think i killed a torroidal.
i finally got back in and checked big red and old yella.
they've been doing a great job given the limits of only doing 4:1 but it was time to open them back up. i knew it had to be a fault with C19/C20 the tanty caps. sure enough, they died when they were back to front and i didnt replace them, then thought there were other problems. replaced with equiv value electrolytics.
fixed, fired up and tested with 1kHz sine - both came up trumps.
i think i must have bumped the 0V tap onto old yellas board from the torroidal after that. came out the back of the 3pin header.
blew a fuse.
all system down.
poor old yella powers up and works fine when i plug it in to big red's torroidal. replaced the 10A IEC inlet and fuse.
do i just call the torroidal dead and replace it at this point?
chris.
i finally got back in and checked big red and old yella.
they've been doing a great job given the limits of only doing 4:1 but it was time to open them back up. i knew it had to be a fault with C19/C20 the tanty caps. sure enough, they died when they were back to front and i didnt replace them, then thought there were other problems. replaced with equiv value electrolytics.
fixed, fired up and tested with 1kHz sine - both came up trumps.
i think i must have bumped the 0V tap onto old yellas board from the torroidal after that. came out the back of the 3pin header.
blew a fuse.
all system down.
poor old yella powers up and works fine when i plug it in to big red's torroidal. replaced the 10A IEC inlet and fuse.
do i just call the torroidal dead and replace it at this point?
chris.
matta
Well-known member
Hi Jakob,
Thanks for the advise and tips. Looking at the data sheet and to answer my own question a transistor like the BC560 has a range from 110 ? 800 Hfe, but the A is 110-220, B = 200-450, C =420-800, which makes perfect sense. So in a general circuit if a certain Hfe is not required you would just use a basic transistor, but if you need to 'fix' the Hfe range for any reason you would use the A,B or C varietals.
Cheers
Matt
Thanks for the advise and tips. Looking at the data sheet and to answer my own question a transistor like the BC560 has a range from 110 ? 800 Hfe, but the A is 110-220, B = 200-450, C =420-800, which makes perfect sense. So in a general circuit if a certain Hfe is not required you would just use a basic transistor, but if you need to 'fix' the Hfe range for any reason you would use the A,B or C varietals.
Cheers
Matt
andre tchmil
Well-known member
I have my G1176 working almost every day fo over a year without any complaints until today.
Signals going thru the unit are really sounding kinda Highpassed around 100 hz and have a annoying 5-8 khz boost +/- 3dB.
I have to confess that I replaced the input pot (1Meg ?? ) recently.
Any idea ?
Signals going thru the unit are really sounding kinda Highpassed around 100 hz and have a annoying 5-8 khz boost +/- 3dB.
I have to confess that I replaced the input pot (1Meg ?? ) recently.
Any idea ?
Andre,
Look for a balancing issue on cabling. I'm pretty sure that's it.
Jakob E.
Look for a balancing issue on cabling. I'm pretty sure that's it.
Jakob E.
synthetic
Well-known member
I feel dumb. I've been looking around for a TLO71, but I can't seem to find one. I'm in the USA, so I've tried Mouser, Digikey, Newark and Parts Express. I think I've found something in the TI "TLC071IP," is this right? Mouser's part number is "595-TLC071IP."
(Sorry, is there a parts-ordering meta?)
(Sorry, is there a parts-ordering meta?)
synthetic
Well-known member
OK, I found a TLO71 but now I'm having power transformer problems.
When I originally ordered transformers for this project, K&K suggested a Hammond 48V/2x24V transformer. However, I notice in Gyraf's instructions that the center tap needs to be grounded. Is this the wrong transformer? Currently, I have it wired as 2x24V: edge and center go to the main board, and the other two wires are not connected. Does this sound correct?
When I originally ordered transformers for this project, K&K suggested a Hammond 48V/2x24V transformer. However, I notice in Gyraf's instructions that the center tap needs to be grounded. Is this the wrong transformer? Currently, I have it wired as 2x24V: edge and center go to the main board, and the other two wires are not connected. Does this sound correct?
dissonantstring
Well-known member
hi synthetic,
have you tried reading this page?
http://www.diyfactory.com/data/transformer_connections.gif
it's found on the meta list which is a great help in most circumstances, just
need to do a little searching.
that being said, your power transformer should have 4 wires for your secondaries. look on the transformer or any data sheets which came with the transformer to see which ones to connect for your center tap. the other two will run to the 24V connections (one wire to each ).
hope it helps.
-grant
have you tried reading this page?
http://www.diyfactory.com/data/transformer_connections.gif
it's found on the meta list which is a great help in most circumstances, just
need to do a little searching.
that being said, your power transformer should have 4 wires for your secondaries. look on the transformer or any data sheets which came with the transformer to see which ones to connect for your center tap. the other two will run to the 24V connections (one wire to each ).
hope it helps.
-grant
synthetic
Well-known member
Right, I have it connected like the "dual isolated secondaries" example. But I'm not reading 24VAC for some reason. I'll keep trying.
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