No, you cannot rely on the length of the leads. That's not the best way to identify the parts.
A few easy ways to identify the parts
- You should be able to put the parts under magnification, and check the marking as ToNi_P mentioned.
- Test them. See the AJzm build guide for specific instructions if you are unsure / need a video. Some 9V batteries (or a PSU), a resistor, and a voltmeter are all that is needed to separate the two.
Enjoy the build!
Patrick
Ha! I remember that I used two magnifiers for this! And the complete part number may not all be there. Pretty smart huh?
^ Same - I use 3.5X magnification for a lot of parts and/or "readers" + a magnifying ring lamp.
Also, my phone takes decent photos. I can usually zoom in tightly enough to read the markings.
Diode markings are fairly standard. A quick internet search usually yields a reliable result.
Also, my phone takes decent photos. I can usually zoom in tightly enough to read the markings.
Diode markings are fairly standard. A quick internet search usually yields a reliable result.
Hi All -
Someone asked a great question, and I am guessing some others may have a similar question.
In a nutshell, the question was: What are these?
They are listed as optional on the packing list. I added them later in the process. So, no... not everyone got them in their kits.
The technical term is - test point helper-outers.
I am a big ol' fraidy cat, and shorting something on a board while I'm trying to hold two probes, turn a tiny pot, and watch a DMM approach a precise voltage isn't something I want to experience (again).
So, if you got those in your kit, and if you use j-hook or mini-grabber probes, you can place those onto the square pads. Attach your DMMs, and rest a little easier that things won't go snap-crackle-pop. Take sip of coffee, twist the pot with your now free hand, watch the DMM delightfully edge toward 14mV and smile.
If you didn't get them in your kit, they are <$0.01 per piece from popular web retailers and/or you can make your own wire loop from an old component lead. Waste-not-want-not.
Attached (now in Post 1 too) are some hopefully helpful diagrams.
Someone asked a great question, and I am guessing some others may have a similar question.
In a nutshell, the question was: What are these?
They are listed as optional on the packing list. I added them later in the process. So, no... not everyone got them in their kits.
The technical term is - test point helper-outers.
I am a big ol' fraidy cat, and shorting something on a board while I'm trying to hold two probes, turn a tiny pot, and watch a DMM approach a precise voltage isn't something I want to experience (again).
So, if you got those in your kit, and if you use j-hook or mini-grabber probes, you can place those onto the square pads. Attach your DMMs, and rest a little easier that things won't go snap-crackle-pop. Take sip of coffee, twist the pot with your now free hand, watch the DMM delightfully edge toward 14mV and smile.
If you didn't get them in your kit, they are <$0.01 per piece from popular web retailers and/or you can make your own wire loop from an old component lead. Waste-not-want-not.
Attached (now in Post 1 too) are some hopefully helpful diagrams.
Attachments
Last edited:
Hi all - I am interested in this build and want to buy the 'Balanced Bundle' while it is in stock. If I order that and the Balanced chassis kit (the 219 Euro one), is there anything else quirky or hand to get I need to source now? I know I have research to do on the power transformers and a few other bits, but think there are options there (I would want to go for the gold to get something good). Thanks!!!
Another Iron Pre SE sings beautifully!
Gladly I think I got the relais thing right with no magic smoke released (fingers still crossed), directly wired one single input now for the lack of relais which are added to next cart..
Really silent as a mouse despite the volume pot is on the front.
A big thank you to @Zen Mod @Nelson Pass @6L6 and @ItsAllInMyHead for this great opportunity.
The amp is housed in a former Cambridge Audio Azur integrated amp case, I have no credit for this, the former tinkerer @sasha70 made the most, I just adapted the Iron Pre to it and benefitting from remote volume control 😉
See some pics, have fun with yours!
Ps. XA252 amp by @schultzsch beneath is also great!
Gladly I think I got the relais thing right with no magic smoke released (fingers still crossed), directly wired one single input now for the lack of relais which are added to next cart..
Really silent as a mouse despite the volume pot is on the front.
A big thank you to @Zen Mod @Nelson Pass @6L6 and @ItsAllInMyHead for this great opportunity.
The amp is housed in a former Cambridge Audio Azur integrated amp case, I have no credit for this, the former tinkerer @sasha70 made the most, I just adapted the Iron Pre to it and benefitting from remote volume control 😉
See some pics, have fun with yours!
Ps. XA252 amp by @schultzsch beneath is also great!
Attachments
Read post #1 from beginning to end, and all should be revealed. If you have specific questions, please let us know. Overall, the answer is no, you don't need anything quirky, but you do need to source several parts to complete the project.
@ItsAllInMyHead - thank you. This post you made was what I was looking for. I'll probably pull the trigger tonight on a Balanced kit and chassis just to get those in my hot little hand while I start looking at the details and other bits.
All these years and finally got smoke. One channel came up fine. The other board brought smoke. Using a Variac, so hopefully not too much damage.
Discovered that I had reversed the BD139 and BD140 on the second board. I have some with the higher gain -16 prefix. Will they work? Also, what else should I replace while changing these out? The BC 55x transistors? The IRF150's?
Discovered that I had reversed the BD139 and BD140 on the second board. I have some with the higher gain -16 prefix. Will they work? Also, what else should I replace while changing these out? The BC 55x transistors? The IRF150's?
yes
yes, 546 and 556, those in BD bases, 1 up and 1 down
also check surrounding resistors
IRFs are good
One other quick question - is there an elegant solution for a single volume control on the balanced version? Either as 2 knobs that are linked and turn in unison, or 1 knob that controls both channels (knowing there will be a blank hole for the other, unused knob)? That is the only thing holding me back from ordering.
Replaced Q1, Q2, T1, and T2. The Q1, T1 side sets up at 15 V just fine. The other side sits at 1V no matter where I set the pot. More to troubleshoot. Any advice?
as I know from numerous occasions, stupidity must be paid for
check all resistors
pull out rest of small BC, check, replace if needed
just in case, check mosfet too, I believe - if not shorted, it's good
just in case, check voltage reference, I believe - if not shorted, it's good
Thanks! Shopping for potentiometers is new to me, so I have ZERO to go off (I don't mean that in a snarky tone!). Would appreciate any guidance on a part that would work or specifications I need to ensure are correct to match the intended performance. I understand I will need to figure out how to wire, mount it, but if I knew what part would work I can start playing with the rest.