How hard it is to replace the rca input on the shindo amplifier?

If you haven’t soldered electronics before, then it may be more prudent to have a local repair shop do it. $100 is standard for this type of job. Typically, they will charge a minimum of 1 hour labor. Like steakster said, it can cost some money to buy good enough soldering iron and actual electronics solder. You might be close enough to the $100 already. The cheaper 25-40 watt soldering irons you can buy at home depot can work, but you may be there for a while heating up solder. This can require a long enough time where you might actually damage some element (like an IC or capacitor, etc.). Some solder points on electronics equipment and PCB can be stubborn, even for my 70 watt Hakko.

As for solder, Home Depot will probably not have the correct stuff. DO NOT buy acid core solder for electronics. For rosin core solder, you’ll want to get as thin solder as possible. Home Depot may have this, but mostly it is the thicker solder that is harder to work with on electronics. Also, for this quality of amp, you’ll probably want to get the better silver/copper type solder. You can get a small roll of Cardas solder from Parts Connexion for $25.

If you are intending to get into doing DIY stuff, then great. Soldering a new RCA input can be an easy job (depending on if you have to deal with PCB mount RCA connector or if they are just wired). Otherwise, it might be better just to have a repair shop do it.

Metcal is supposed to be one of the best stations, but I have never used it.  This particular model is only 35 watts.  The tip determines the temperature, so if you get it, make sure you have a series 600 or 650 tip.  Don't use anything too hot or you're likely to heat and lift the contact pads off the PCB.

My old Weller WTCPT had the same type of mechanism where the type of tip determined the temperature.  It could very well be that I was using a low temp tip (this was many many years ago).  However, I'm totally spoiled with my Hakko - so I may be jaded.  It could very well be that the Metcal or Weller may work out okay.  If it was between the Metcal and Weller, I would probably jump on the Weller because of power output and temp controllability.

Used is not bad, as long as the item was kept in good condition.  I bought a used Hakko 470B desoldering stations years ago and it's still going strong.

I used to own a Weller WTCPT, which is a 42 watt iron. It just didn’t heat enough for me and that made it just harder to use. The Weller WES51 is 50 watt, which is just a little bit better. If that’s what you have, then use it if it works for you.

I moved on to a Hakko FX-951, at 70 watts. It heats the tip really fast (generally within 10 seconds) and it’s very effective in keeping the tip hot. I can get in and out really fast when soldering connections, unless they are larger pins/metal. It’s digital readout/controlled and it’s really great if you serious about DIY, but it is expensive at $236+.

If you want a good quality inexpensive iron, look at the Hakko FX-888D. It’s discontinued, but you can still get it new at multiple sources for about $100. It’s a little bit less power at 65 watt. Main differences are:

- sleep mode on FX951 only
- tips shape selection which is higher for the FX951
- tips technology:
• FX951 use cartrige so the heating element is into the tip, every time you change tip you have a new heating elemnt
• FX888D use standard tip, less selection, the heating system is into the handle sold as spare part in case of need ($20)
- tips price, FX951’s tip are much more expensive the FX888D’s tip like 15euro Vs 5 euro

The Weller irons are very nice, but they are a lot more expensive for what you are getting.

If you want a cheaper iron, one of the best Chinese imports is the Quick 3103 analog station ($65) or the Quick 3104 digital ($85). Both of these are 70 watts as well. I use the Quick 861dw hot air workstation after a lot of research. The Quick products are extremely well made and high quality for Chinese stuff.

Then you could always go for the bargain basement Chinese import stuff on ebay for $50 or less (like the yihua or generic or whatever). They may look like they come with more stuff, but they are basically slapped together with a ton of low quality components. Be careful because these can actually become fire hazards, since the internal wiring is not always done properly. I would avoid, unless you were able to pull it apart and verify all electrical wiring is done properly and fix their mistakes.

The $100 Hakko 888D will be just fine for you. It’s, basically, almost just as powerful at the 951. The main difference is the usability and tip options. The 888D will have good tip options if you are doing basic connections and through-hole elements (such as resistors, capacitors, RCA inputs, etc.). You would want the 951 if you need the advanced type tips, such as quad-tip, tunnel, spatula (these are used primary for SMD parts, such as surface mount op amps and ICs). The 951 has a sleep mode where it shuts down power to the iron if you let it sit in the iron holder for a number of minutes (the 888D does not). It also has a different way to set the temperature/settings. The 888D will heat the soldering tip just as well as the 951 and keep it hot.

The following two videos are excellent on the overview/review of proper soldering tip maintenance and using the Hakko 888D:

https://www.youtube.com/watch?v=_exJEnZN9QI

https://www.youtube.com/watch?v=y5weXfQvCgM

It sounded like you were in a hurry to get an iron so that you could solder this weekend, lol.  If you have the patience and budget, I'd say get the 888D.  I would also recommend a 1.6mm chisel tip (part T18-D16 for the 888D).  I have found that it's a really good all-around tip that can be used in a lot of situations.  Much better than the smaller pointed tip that comes with the iron.