• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Yamaha newbie A-700 resto thread

analogwisdom said:
10-4. I should've thought a little harder or waited for someone to tell me otherwise before I made the order. I will make another one.
Click to expand...
It happens.

I edited in some transistor links in my earlier post.

Moving on,
For the 2SA1306A/2SC3298A I used the ON Semi MJE15033G/MJE15032G when I worked on an A-1020. That was something like 9+ years ago and the owner reports that the amp is still working great so I'll call that a success.
But the KTA1659/KTC4370 that Soundscape mentioned in post #121 look very interesting. Coincidentally I just ordered 50 of each of them on Monday. If they turn out to be as good as some members say they will be a good sub for a number of NLA drivers.
https://www.lcsc.com/product-detail...C_KTA1659A-Y-U-PF_KTA1659A-Y-U-PF_C69800.html
www.lcsc.com

KTC4370A-Y-U/PF | Single Bipolar Transistors | KEC | LCSC

KTC4370A-Y-U/PF Single Bipolar Transistors by KEC. Features - and 1uA. From $0.2517, 626 in stock. Datasheet available.
www.lcsc.com www.lcsc.com

Here are some other subs. Not all of them are ones that you said are bad but just in case I'm including them.

2SA970GR = KSA992FTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSA992FTA?qs=JV7lzlMm3yLxzxW6hzRppQ==
2SC2240 = KSC1845FTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSC1845FTA?qs=sGAEpiMZZMshyDBzk1/Wi8oN7VHZ91Ok7yYQ9zR8%2B88=
2SC1815Y = Ksc1815YTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSC1815YTA?qs=sGAEpiMZZMshyDBzk1/Wi8oN7VHZ91Ok9NiSl87vuMg=
2SA1015-O = KSA1015YTU
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSB1015YTU?qs=ljbEvF4DwOP0LgPE7HhE1A==

Double check your pin outs! Just in case I got one of these wrong, because a few of them (KSA992 I think) have alternate pin configurations.

Cheers,
James
 
Bratwurst7s said:
It happens.

I edited in some transistor links in my earlier post.

Moving on,
For the 2SA1306A/2SC3298A I used the ON Semi MJE15033G/MJE15032G when I worked on an A-1020. That was something like 9+ years ago and the owner reports that the amp is still working great so I'll call that a success.
But the KTA1659/KTC4370 that Soundscape mentioned in post #121 look very interesting. Coincidentally I just ordered 50 of each of them on Monday. If they turn out to be as good as some members say they will be a good sub for a number of NLA drivers.
https://www.lcsc.com/product-detail...C_KTA1659A-Y-U-PF_KTA1659A-Y-U-PF_C69800.html
www.lcsc.com

KTC4370A-Y-U/PF | Single Bipolar Transistors | KEC | LCSC

KTC4370A-Y-U/PF Single Bipolar Transistors by KEC. Features - and 1uA. From $0.2517, 626 in stock. Datasheet available.
www.lcsc.com www.lcsc.com

Here are some other subs. Not all of them are ones that you said are bad but just in case I'm including them.

2SA970GR = KSA992FTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSA992FTA?qs=JV7lzlMm3yLxzxW6hzRppQ==
2SC2240 = KSC1845FTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSC1845FTA?qs=sGAEpiMZZMshyDBzk1/Wi8oN7VHZ91Ok7yYQ9zR8%2B88=
2SC1815Y = Ksc1815YTA
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSC1815YTA?qs=sGAEpiMZZMshyDBzk1/Wi8oN7VHZ91Ok9NiSl87vuMg=
2SA1015-O = KSA1015YTU
https://www.mouser.de/ProductDetail/onsemi-Fairchild/KSB1015YTU?qs=ljbEvF4DwOP0LgPE7HhE1A==

Double check your pin outs! Just in case I got one of these wrong, because a few of them (KSA992 I think) have alternate pin configurations.

Cheers,
James
Click to expand...
Thanks for the info, I appreciate it. I actually have a decent stock of those last you linked, they were all used in my Kenwood project and I had just ordered a couple hundred of each (except the KSB1015). I figured with transistors and common value capacitors it's good to "over-order" since I'm starting out, to build a stock up.
 
Last edited:
analogwisdom said:
Thanks for the info, I appreciate it. I actually have a decent stock of those last you linked, they were all used in my Kenwood project and I had order a couple hundred of each (except the KSB1015). I figured with transistors and common value capacitors it's good to "over-order" since I'm starting out, to build a stock up.
Click to expand...

OK, now the thing is, when it comes to raw electronic troubleshooting the other guys that joined in are way better than me so from this point I am going to slide a bit to the sidelines so that I don't get in the way.

But I would say that is is essential to first find and fix the original missing channel problem before addressing the Chernobyl incident.

Cheers,
James
 
Bratwurst7s said:
OK, now the thing is, when it comes to raw electronic troubleshooting the other guys that joined in are way better than me so from this point I am going to slide a bit to the sidelines so that I don't get in the way.

But I would say that is is essential to first find and fix the original missing channel problem before addressing the Chernobyl incident.

Cheers,
James
Click to expand...
Chernobyl incident definitely got a chuckle out of me. Once the replacement desoldering gun gets here, I am going to do my best to again disassemble the relevant boards from the chassis and trace the path of that left channel input to see where the breakdown might be happening. Taking apart the switches is a daunting task, but I'll also do my best to not fudge that up. Thankfully I found a guide that should help with that: Hifi-Retro link (not in English, but Google Translate works well for this page).

As far as your self-proclaimed lesser experience, you have more than myself and I appreciate all your replies and advice all the same. My hope is to one day be one of the people around these parts answering questions instead of asking them, but I have a very long way to go, and a lot of listening to others to do.
 
Last edited:
analogwisdom said:
Chernobyl incident definitely got a chuckle out of me. Once the replacement desoldering gun gets here, I am going to do my best to again disassemble the relevant boards from the chassis and trace the path of that left channel input to see where the breakdown might be happening. Taking apart the switches is a daunting task, but I'll also do my best to not fudge that up. Thankfully I found a guide that should help with that: Hifi-Retro link (not in English, but Google Translate works well for this page).

As far as your self-proclaimed lesser experience, you have more than myself and I appreciate all your replies and advice all the same. My hope is to one day be one of the people around these parts answering questions instead of asking them, but I have a very long way to go, and a lot of listening to others to do.
Click to expand...

The term Chernobyl incident is as far as I know copyrighted and trademarked by Avionic. Used (hopefully) with permission.

Passing on information and helping each other is the glue that makes this a powerful place. 10 years ago I started out in exactly your position with a A-1020 and was able to repair it because of the help of other members. We pay it forward here.

Cheers,
James
 
analogwisdom said:
Thanks for the info, I appreciate it. I actually have a decent stock of those last you linked, they were all used in my Kenwood project and I had just ordered a couple hundred of each (except the KSB1015). I figured with transistors and common value capacitors it's good to "over-order" since I'm starting out, to build a stock up.
Click to expand...

Btw, It seems that you are into Kennwood gear. I will be stepping to that zone for the first time this summer. I bought a L-1000C pre-amp last month but I figure it will be at least June before I have time to touch it. Stay tuned for a thread over there.

Cheers,
James
 
Bratwurst7s said:
Btw, It seems that you are into Kennwood gear. I will be stepping to that zone for the first time this summer. I bought a L-1000C pre-amp last month but I figure it will be at least June before I have time to touch it. Stay tuned for a thread over there.

Cheers,
James
Click to expand...
Can't wait to see it. I love Kenwood so much. Once I'm finished with this project, I'll probably try to scoop up some Kenwood unit to work on, probably a lower-end integrated that's less complicated.
 
analogwisdom said:
Can't wait to see it. I love Kenwood so much. Once I'm finished with this project, I'll probably try to scoop up some Kenwood unit to work on, probably a lower-end integrated that's less complicated.
Click to expand...

I have been wanting to try a Pre-amp that has balanced inputs/outputs. I have been told that the L-07C is a better pre but it doesn't have balanced jacks, no remote and is too tall to fit in my new rack.
The L-1000C looks very interesting inside, has balanced and remote and will fit in the rack and I am very curious to hear if it can beat my CX-1.
 
I found this flameproof resistor for a replacement for R114 (33Ω, 1/4W): FRN25J33R

However, I am having trouble finding 1/4W flameproof/fusible resistors for the other two replacements I need (R302, 220Ω and R394, 1.8KΩ).

I'm not sure what I should do. I looked for 1/3W options and even those weren't available. There are these Vishay RL07 series I found that are the correct values, but they aren't flameproof:



Would these be okay to use instead?

edit: I found this 220Ω 1/4W fusible: FRN25J220R. Damn Mouser search not showing you parts that are "end of life" but still in stock, I had to use Google. Still having trouble with the 1.8KΩ part.
 
Last edited:
avionic said:
What's the problem if they are still in stock ? Grab 'm before they are no longer in stock..
Click to expand...
I am getting them. The problem is that Mouser doesn't show you parts that are obsolete, or end of life, with the search tool on their website, even if they're in stock. You have to use Google or Octopart, or type in the series name on Mouser to find them. It's just annoying. Another example is Nichicon UFG/UKZ caps. If you search for 470uF/25V caps on their search tool, it doesn't show this UFG that is "end of life", but they have over 3,000 in stock.

eiraved said:
99% of the parts left remaining after restoration of the A-700 are well past their "end of life" spec, so don't worry about the new off the shelf parts.
Click to expand...
See above, was just annoyed by Mouser's search tool.

Anyway, I can't find a 1.8KΩ 1/4W fusible/flameproof resistor anywhere... Not sure what to do there.



edit: https://www.arcade-electronics.com/NTE-QW218-Metal-Flameproof-Resistors-p/nte-qw218-bu.htm

Finally found this, but I have no idea about the website, and I've seen a lot of people saying to avoid NTE...
 
1000008747.jpg

Mouser packaging makes no sense to me, lol. The other devices just came loose in the regular anti-static bags, but for some reason this one is in a fancy little box. Is Mouser trying to propose to me?

I accept!
 
analogwisdom, I'm thinking I wasn't clear enough earlier, or you missed my comment.

The OnSemi NJW3281G/NJW1302G are a very good choice as outputs for you if you use the adapter plates.
But I have some new 2SA1493/2SC3857 MT200 parts sitting here, unused and I don't really need them, enough for both channels of your amp.

Contact me in a private conversation if you would like to have them. It is no problem at all. Note that we are not talking about a sale or money. I said "if you would like to have them".

Cheers,
James
 
You must log in or register to reply here.
Back
Top Bottom