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Ramsa PA amplifier repair attempt of dead channel 

JohnAudioTech
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29 окт 2024

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Комментарии : 49   
@jimcatanzaro7808
@jimcatanzaro7808 3 года назад
It’s amazing how fast the bench gets messed up
@EuroScot2023
@EuroScot2023 3 года назад
Excellent work. Ok, you're no Mr Carlson or Xraytonyb but you know your electronics and show what can be done on a limited budget at a pure hobby level. I applaud your efforts.
@j.fanning8158
@j.fanning8158 3 года назад
Nice going on the diagnosis and repair ! Glad you got it working again. Thanks for sharing this on RU-vid.
@johnsonlam
@johnsonlam 3 года назад
Awesome John! If repair can make a living I'll probably quit my job, I love to bring things back to life again, it's satisfying.
@martinda7446
@martinda7446 3 года назад
They weren't kidding when they said the channel was 'out'!😸 Edit Doh you got me..I shoulda listened another five seconds before commenting...
@jeremiahchamberlin4499
@jeremiahchamberlin4499 3 года назад
Good job! Helpful video. Gives me hope that I can get some of my stuff working. Sharp eye to catch that diode.
@misterjib
@misterjib 3 года назад
Satisfying repair.
@tubeDude48
@tubeDude48 3 года назад
Don't forget: Electronics old and new, plus: David Tipton
@PeterMilanovski
@PeterMilanovski 3 года назад
John, it's great to hear that comments do get through and not ignored, I understand that sometimes we can be or seem to be difficult but sometimes we are just trying to get across something that we feel is important. The majority of comments made by me in most electronic video repairs is usually about capacitors! All that I'm trying to do is bring awareness, I can't tell you how many times that I have watched someone working on a repair and see the person go over the capacitors in circuit with an ESR meter and claim that they are all fine even though I can see that the capacitor has leaked out it's electrolyte all over the PCB! And that same person later on still has a problem and can't seem to figure it out, he even say's that he checked the capacitors so it can't be them! I don't know, has RU-vid created a new phenomenon that allows the viewer to see the problem even though they are somewhere else in the world, is this something that someone is going to come out and say that this new phenomenon has been discovered by doctors working on a surgery remotely? Who knows? What I do know though, is that there's only one way at this present time to check capacitors is out of circuit! I wish that I could provide you with a method for this mundane task but I don't. I just don't want this Oh! I checked the ESR and everything is fine to get into the mind of people as this is the only thing that needs to be tested! I'm sure that you have seen Mr Carlson's capacitor tester, it doesn't check for ESR, it checks for DC leakage which is the capacitor failure mode that is responsible for destroying just about every single component that has ever failed in the history of electronics! And yet the message that is being output is that if ESR is fine, then everything is good! I'm just trying to save people a lot of headache trying to fix something, it's not about just about replacing capacitors, it's about knowing what their condition is like. Then you either choose to keep the original capacitor assuming that it is good or put in a new one! That's all! So all that we have is to test for ESR, DC leakage and capacity! Capacity can be a giveaway to condition, it should always measure just under it's rating, if it's too low, it's bad, if it's too high it's also bad. A capacitor that leaks DC takes longer to measure capacity so the tester see's a larger value... Mr Paul Carlson and XRayTonyB's channel are amazing. Their dedication to repair is second to none... Your channel on the other hand offers something different, the thorough testing that you put into amplifiers that are within reach of the masses is a great formula! It's what keeps me coming back each and every single time. So basically something that you are doing is working! Keep up the great work... I like the Ramsa but I can't really say why, it could possibly be something special when working correctly or it could be nothing special? If it's quiet and has decent output, it could be valuable to someone?
@jimcatanzaro7808
@jimcatanzaro7808 3 года назад
Love your channel i had to stop getting new projects it was making to much of a mess
@svtcontour
@svtcontour 3 года назад
I have one of these. Sound quality is very VERY good overall
@mrb.5610
@mrb.5610 3 года назад
Looks decent enough build quality which is usually a good sign !
@svtcontour
@svtcontour 3 года назад
@@mrb.5610 Ya I think mine is one step up in power level but pretty similar. I use mine for hi-fi use. It displaced my Threshold Class A amp! I know its subjective but I found it to sound just as detailed and correct but tighter and better bass as well.
@bobking7347
@bobking7347 3 года назад
That Amp sounds pretty good, you should use it somewhere, the fan doesn't seem to loud either.
@Enigma758
@Enigma758 3 года назад
Did you measure the voltage going into the diode in order to choose a comparable replacement?
@1pcfred
@1pcfred 3 года назад
OMG authentic vintage JRC 4558 op amps! They're one of the Holy Grails of the guitar world. Worth big bucks. There's only so many of them ever made or left now. They did reissue them. But the reissues are not the same tone as the originals. So you have something on your hands. Whether you know it, or not.
@envisionelectronics
@envisionelectronics 3 года назад
You want a million of them for nearly free? So many Japanese mixer boards used them. Warm up your desoldering iron!
@1pcfred
@1pcfred 3 года назад
@@envisionelectronics I have a few I found in some vintage gear. I don't strip parts with an iron though. Salvage is *NOT* board rework! So being as the goals are different methods vary too. Personally I use a solder pot myself. In rework the board is the most important component. In salvage the board is worthless and the parts themselves are the only thing of value.
@paulb4661
@paulb4661 3 года назад
Give JRC's Muses a try, there are many far superior ones looking at the specs, but correctly implemented they can make your jaw drop soundwise.
@PhuckHue2
@PhuckHue2 3 года назад
The JRC 2068 is better
@1pcfred
@1pcfred 3 года назад
@@PhuckHue2 It wasn't used in the TS-808 which every hair metal band in the 80s used.
@Fireship1
@Fireship1 3 года назад
Nice troubleshooting and repair!
@EngineeringEssentials
@EngineeringEssentials 3 года назад
What you're planning to do with rescued amplifiers?
@mrb.5610
@mrb.5610 3 года назад
Dunno why some manufacturers cover their circuit boards with goop - I recently repaired a Dell monitor that had a fairly common fault with SMD resistors dying that are covered in a big blob of silicone .... . I mean *WHY* ??? It works just fine without the silicone blob stuck all over the PCB !
@zeegrewal3175
@zeegrewal3175 3 года назад
hey john .. love your videos .. have learnt quite a bit . i have a question if you dont mind and can answer please . I am trying to replace the tiny speaker in the bluetooth audio airpod ( third party bluetooth ear audio headset ) . What amplifier would you suggest that can drive a 100W speaker ? So take input from the two wires from headset and amplify them and feed to the large speaker. Thank you.
@JohnAudioTech
@JohnAudioTech 3 года назад
You can drive a 100w speaker with about any amplifier. Speaker sensitivity and other parameters should be more of a concern. It depends on how loud you want it and the frequency response. A lot of the amplifier boards I've reviewed on this channel could work.
@pliedtka
@pliedtka 3 года назад
Power amp section seems OK. Big Sankens but the preamp, driver section rather complicated. Yeah and the corrosive glue issues.
@andymouse
@andymouse 3 года назад
Great work, is a PA amp just very powerful but not audio quality, or is there something more please ?....cheers.
@JohnAudioTech
@JohnAudioTech 3 года назад
I'd say so. Most have distortion ratings in the 1% down to perhaps .1% range. They are also built heavy and rugged for road use.
@CoquiAudio
@CoquiAudio 3 года назад
they gave it to you free? wow! that never happens in Puerto Rico 😂
@bjsmobilesoundtv3063
@bjsmobilesoundtv3063 Год назад
Nice. Sir can I give me the systematic diagram of wp 9110ramsa sir please
@MickeyMishra
@MickeyMishra 3 года назад
1:59 HAHAHAHHAHAH Its TRUE! XrayTonyB and 12V Vids for some reason all seem to me like the same people.
@TheTrueVoiceOfReason
@TheTrueVoiceOfReason 3 года назад
12VoltVids repairs quite a bit, and Gregg's Vintage Workshop does a lot of old restoration type of videos
@mrb.5610
@mrb.5610 3 года назад
shango066 does a good line in street find TV 'resurrections' complete with plenty of free sarcasm thrown in as well. David Tipton is another one I'd recommend - not just the usual 'replace the electrolytics' videos but also some excellent case and mechanical turntable restorations as well.
@TheTrueVoiceOfReason
@TheTrueVoiceOfReason 3 года назад
@@mrb.5610 I watch just about all of Shango's videos. It's absolutely amazing how much can be done with such suspect parts.
@JohnAudioTech
@JohnAudioTech 3 года назад
@@TheTrueVoiceOfReason Shango is who gave me the idea for testing capacitors in circuit by putting audio through them. I just do it at a low level so not to harm or forward bias silicon junctions.
@TheTrueVoiceOfReason
@TheTrueVoiceOfReason 3 года назад
@@JohnAudioTech yep, same here. It's a technique I had never thought of until he showed it, and I was like " that's so simple and direct, why wasn't it ever taught anywhere else? And why didn't I think of that?" It just goes to show that you don't necessarily need $100's - $1000's of equipment to do a good bit of the normal troubleshooting, you can quickly determine/isolate parts/areas just by using a known good cap (à la Shango) and by close inspection as you did here. Does it catch everything, by all means no. But it does get you a good start. That's why I watch so many of "you guys", you never know what bits of really good info will come out during a video.
@SlinkyStoney
@SlinkyStoney 3 года назад
I didn't know that RAMSA was a Panasonic.
@DAVIDGREGORYKERR
@DAVIDGREGORYKERR 3 года назад
Looks like that that PCB is a basket case maybe that should have used a compound that does not corrode component leads after 20-30 years.
@DolganoFF
@DolganoFF 3 года назад
Ramsa were PA amps and speakers of doubtful quality and cheap price :)
@1pcfred
@1pcfred 3 года назад
They may have been cheap back in the day but the passage of time has made some parts in there extremely valuable today. Specifically those authentic vintage JRC 4558 op amps. Which have been reissued they're so sought after. But the originals are still where it's at. Although the reissue has diluted the market. People in the know will pay big for the real thing. The tone of the originals is unmatched.
@bjsmobilesoundtv3063
@bjsmobilesoundtv3063 Год назад
You have diagram sir ramsa 9110 please give me copy sir thank you
@moodyga40
@moodyga40 3 года назад
Hi end Panasonic easy repair
@aurthorthing7403
@aurthorthing7403 3 года назад
Make it squawk....
@obedjimenez2624
@obedjimenez2624 3 года назад
Mr. Carlson is not taking any repairs and X-ray to y b also , not even if you join patron .
@mehedihasan6073
@mehedihasan6073 3 года назад
They probably use the black gunk stuffs as a self killing agent intentionally? So after a fair amount of time the items will fail mechanically as the electronics and design are so good they will run for ages otherwise?
@JohnAudioTech
@JohnAudioTech 3 года назад
I just think the glue goes bad over time like some old plastics turn brittle or pot metal warps or cracks.
@jeffm2787
@jeffm2787 3 года назад
It's been slimed....
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