Not so sure about that.
Especially in high thermal stress, leaded solder beats lead-free.
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All I meant by that is manufacturers have no choice.
Personally I use leaded solder.
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Hey so just out of curiosity, started reading up on Op amps, CMRR, (Differential/V1=V2), what the hell Decibels are (The answer, may suprise you), Slew Rates and Oscillation effects when increased compared to Gain-Bandwith Product, etc.
So like, I was curious, one of the Op-Amps inside the amp for example, is a TL072CP (Lets call it Model 0 for reference later):
https://www.mouser.com/ProductDetail/Texas-Instruments/TL072CP?qs=sGAEpiMZZMtCHixnSjNA6I%2FK8QDhU1zCEHGq3qQnSxU%3D
There is are two slightly improved versions of this Op-Amp, the TL072ACP and TL072BCP:
So these two Op-Amps are identical in almost every way to Model 0, both are Texas Instruments, all have the same GBP and Slew Rate, both are two channel, use the same case, same bias current, same supply current, same supply voltage.
The only difference is that Model A and B both have slightly lower Max Operating Temps, going from 85 C in Model 0 to 70 C in Model A & B. Model B specifically has an input Offset Voltage of 3 mV instead of 6 mV like Model 0 & A.
So for my first question, Model 0 and Model A are near identical, but Model A seems to have slightly better CMRR (Common Mode Rejection Ratio), so is this technically a slightly better drop in improvement to Model 0 since everything else electrically is identical, even slew rates and Gain-Bandwidth product?
Second Question, Model B is Also Practically Identical, and also has a better CMRR than Model 0, with the one difference being a 3mV Input Voltage Offset instead of a 6mV Input Offset like Model 0 and Model A, so what would this affect in the performance of the Op-Amp if replacing Model 0 in the circuit with Model B?
I know I’m getting ahead of myself since I haven’t even tested if the Amp works since I don’t get the fuses until Tomorrow, but kinda want to get the ball rolling on some slight component updates if I can get it working again.
Oh shit, just a funny thing I noticed, if you search up “IEMS Phonitor” into google, this forum is on the first page, just scroll down a bit, On my search results at least, so we did it bois and boisettes, we made it to the front page of Google. Unrelated, but pretty funny.
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Also just out of Curiosity (Again), say when the fuses get here, I have two test IEMs to plug into the amp (Cheapo 4 dollar IEMS) and they break and blow the fuses again, I read somewhere that sometimes a bad Relay may cause this to happen due to more voltage getting through than what should get through.
The Relay used in the amp is a DS2Y-S-DC12V (Lets Name it 2Y for Reference):
https://www.mouser.com/ProductDetail/Panasonic-Industrial-Devices/DS2Y-S-DC12V?qs=sGAEpiMZZMs3UE%2BXNiFaVCLW1ZA8WQBLokc2Dgfcyjc%3D
This relay is a special Factory order Relay, and is out of stock, BUT, it has a very very close counterpart, the DS2E-S-DC12V (Lets Name it 2E for Reference):
https://www.mouser.com/ProductDetail/Panasonic-Industrial-Devices/DS2E-S-DC12V?qs=sGAEpiMZZMs3UE%2BXNiFaVCLW1ZA8WQBLg4UmGKr%2FwRE%3D
Now based on the Data Sheets, they seem to be almost identical as well, save for one detail, being contact rating. The contact rating for the 2Y is 3 Amps at an unknown Voltage rating, while the 2E is rated for 2 Amps at 30V. Now what is weird, is that the Contact Current Rating, are identical at 3 Amps.
Now my understanding is that the contacts on the 2E can handle 60W (2*30) of power, while the 2Y can handle an unknown amount of power, but is rated at 3 Amps both the Contact rating and Contact Current Rating. If I were to replace all the 2Y relays with 2E relays, is the 2E suitable for this application, or does the 3 Amp vs 2 Amp at 30V rating more substantial than I think it is, even though the Contact Current Rating is identical at 3 Amps?
Also you mention Thermal Stress, and while this intrigues me since the PCBs for the Tube Amp I’m making use Lead solder, I was planning on using Lead Free for the Point to Point wiring. How much thermal stress are we talking here?
Will anything happen to Lead Free Solder at lets say, idk, 70 Degrees Celsius (I mean 5 Amp 6.3 Volt Heater Currents, like a Dual Triode 6528 on an Octal base is pretty hefty, and there are some tubes out there that can melt solder too, especially 6C33Cs, although those are 7 amps at 6.3V in a smaller 9 Pin Envelope and all of that from a single Triode)?
Also by thermal stress, do you mean sudden changes to temp, or just extreme temperatures in general, like very hot for a long time (Not melting point though), or very cold for a long time?
Oh also, you mentioned the vertical boards to be power regulation, now, don’t get mad at what I’m about to show you, it’s more for educational purposes, but:
Now, the point of the video here isn’t to say the THX 789 is better (M0N would kill me, especially since he made this DIY forum, jk tho), the actual point is to show an interesting tidbit in the video, being that at one point when they open the Amp, they point out a power regulator at the input where the power brick feed the amp DC.
Interestingly, it appears to be very similar in structure save some key differences to the vertical boards in the Phonitor 2, idk saw it and kinda thought about what you said earlier, so yeah, now it makes a bit more sense since I can see a similar design being used there too.
Pretty interesting how certain topologies are used to similar extents in other amps, then again, it’s pretty common for tube amps to be similar internally to one another, like the Darkvoice vs Crack for example, so whose to say SS can’t do the same.
Obviously the THX and the Phonitor 2 aren’t really that similar as in the case with the DV and Crack, but to see that certain aspects of SS DNA are shared between one another in a similar phenotypic and even genotypic fashion, idk, it’s intriguing.
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I mean big temperature differences.
When one end if the solder joint is room temperature and the other is 120F (50°C), that joint will fail after a while (2-ish years, just out of warranty).
I love learning more!
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Ok I got the fuses, too scared to turn it on tho, what’s the worst case scenario situation if I turn it on and it fails again (I’m just turning it on, nothing else is plugged in atm).
Will it blow up or something or what, I have the case open so I can see it from the inside when I power it on, I made sure the board Grounding is well done (Even though it seems the power supply is floating since nothing inside uses ground, just the screws holding the PCB down, so I guess it’s a safety feature more than anything else in case something goes wrong?), the transformer has been set back into it’s original position, the Diode seems to be correctly installed, no damage since I was using lead solder and low temperatures, so it never got too much heat to it. The Op-Amps have been placed in their correct orientation (I took pics before dissembling it to make sure). Everything seems fine, kinda worried it’ll go nuclear if I turn it on tho.
u can still buy lead solder. look for any solder that doesnt specify lead free. PE has a few options with lead in them. granted the lead% if small nowadays compared to when i was growing up for instance. I first soldered with pure lead solder lol. stinks more tho. and like others have mentioned, i am not sure it matters anymore. lead free solder is great now. i personally use solder with 5% silver as i like it and it works well. its also great for tinning wire with the silver content.
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Yeah, I use lead free with 4% silver on point to point and larger components, but prefer to play it safe and use easier to handle and lower temperature lead solder as to not damage the smaller components.
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i also have not really built any electronics lately, if i had a ton of soldering i would probably use lead free without silver. both for cost savings and easier to work with. the silver does need more heat to flow.
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and its slightly off topic, but since we talking soldering, chisel tips ftw for tinning wire.
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I mean I buy my wire from Remington Industries, price isn’t too bad, managed to get 250 ft of tinned 18 gauge wire for about 35 bucks, so I don’t have to worry about having to tin my wires, it’s just, get the wire, put it though the hole, secure a mechanical connection, then solder, and voila, you could pull all you want, that wire is never leaving that hole.
oh nice! thats a good price to. wire works well? never heard of them before
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Oh yeah, their stuff is pretty good, easy to work with, easy to strip the wire since it fits perfectly into the 18 Gauge hole of my stripper, I bought mine with a 600 V insulation, they also have it for 300 V but they’re both the same price, just the material is a bit different.
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It’s 38 Bucks for a roll of 250ft tinned 18 gauge with PVC 600 V insulation, idk much about prices but that seems to be pretty good, and shipping is pretty quick too.
Maybe take video while you turn it on. You know…just in case.
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Yeah I’ll do that, when you see the camera suddenly jump just know that was me shitting my pants seeing a Phonitor 2 going nuclear.
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Get a cheap air duct, PC fan and some cardboard. DIY fume extractor.
I mostly use Sn60Pb38Cu2 solder, sometimes Sn96.5Ag3Cu0.5
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