Technics M245X Recap Job | Aligning the Record Amplifier EQ
ฝัง
- เผยแพร่เมื่อ 2 พ.ค. 2024
- In my first video on this unit, I quickly discovered that it has a case of bad capacitors causing popping and a loss of treble in the audio. Let's do a full recap job so I can double this deck's damage to my wallet.
I'll also try to figure out how to do a record amp EQ alignment for the very first time, and I'll probably do it wrong.
Facebook: / theweatherwolf
Insta: / oklawolf
Camera gear I use:
Nikon D800, Nikon Z50, iPhone XS Max & 13 Pro Max, DJI Action 3, Autel Evo Nano+, Autel Evo Lite+, DJI Mini 3 Pro
Music:
senpai vaporwave - 輝き (senpaivaporwave.bandcamp.com)
senpai vaporwave - T.E.H.Y.2 C_O_M_E『420』
猫 シ Corp. - Martini Girl (catsystemcorp.bandcamp.com)
Gwen Guthrie - Fat Off My Back - บันเทิง
Update - the bloated low end was the 0.1uF capacitors in the recording amplifier. I've now changed them back to their original values using Fine Gold parts. She'll give a 2 head Nak machine a run for its money now, but tends to sound a mite shrill with tapes recorded on a truly flat machine like the A&D GX-Z9100.
Always enjoy watching youre vids
Sounds good to me!
16:00 I would go with the original installed values in Technics decks, rather than what the service manual says. This is most likely the cause for the recording EQ issue you are having. There is a similar error (or a later factory correction that was not addressed in the SM) with the Technics RS-B555/B565, where C35 and C36 are 1uF in the SM, but the deck has 4.7uF installed. Vince666's recap list mentions this, however I forgot about it and systematically recapped one RS-B555 by the SM, later to find that the recording frequency response was severely lacking bass. So, lesson here is - replace with what is installed in the deck, not what the SM says (at least with Technics equipment). Hopefully that will fix the issue.
That's what I was thinking, but other owners have mentioned the same issue so I figured it's just how they are with the factory dual op-amp. I've been trying to decide if I want to throw one of my M2114s in there or not to see how that sounds.
Yep, that was it. Replaced the 0.1uF UKLs with 1uF UFG, did a test record, and that got the low end under control.
@@Oklawolf Good to hear that solved the issue. :) I need to put this in my notes as well.
I like youre video's , but you need a "old "analog AC millivolt meter with high enough bandwith . It's a nice DBX deck !
Nice job there but why not re-capping the entire unit?
Just a curious question: If the caps for such a project are so expensive, why didn't you test them all before hand, and then just replace the caps that were defective and the ones you deemed on the edge?
The defective Elna didn't measure bad in circuit. It had to come out first, and even then it still tested good for ESR. It was the abnormal delay in the tester measuring it that told me it was electrically leaky. I likely wouldn't have caught it had I not blanket replaced them all. With that said, next time I work on an old Technics, the dark blue SU parts will only be replaced if they test bad or are physically leaking. All old Elna caps will be considered suspect and immediately replaced like those lilac wonders.
Why would you put those low life 1000 hrs caps instead of Elna's or long lasting Nichicons ? Even though they're 'audio' grade they offer no improvement whatsoever.
Each cap has a specific purpose. UES are the best sounding and least distorting capacitors, by objective listening and measurements, confirmed by many (including me), and they do improve A LOT the sound, especially in most non-DC circuits. That 1000hrs is rated at a specific temperature (85 degrees). You are not putting those in hot zones or in fast switching power supplies, they are for the signal path in audio circuits, which means that in such normal conditions, they will last decades. And don't let me started on ELNA caps. Overrated garbage sonically (SILMIC II specifically), and in old equipment they are time bombs.
You're wrong on everything Nichicon gold sound just as good as those green caps and last alot longer. This is confirmed by laboratories not just diy repair stereo peddlers.