[DefQon]

Picked up a cheap Marantz PM-32 integrated which was entry to mid level back in the 80's. Drives my LCD2's better than all the Violectric and Burson range I've owned and tried.

 

[tribestros]

Sounds about right. I'd recommend taking it to a vintage shop to get it cleaned up and some parts replaced. Or, if you're a DIY'er, just do it yourself. Buy some Deoxit, canned air, and a cheap toothbrush, and clean the boards carefully.

 

[tribestros]

Sounds about right. I'd recommend taking it to a vintage shop to get it cleaned up and some parts replaced. Or, if you're a DIY'er, just do it yourself. Buy some Deoxit, canned air, and a cheap toothbrush, and clean the boards carefully. These things'll last forever if you take care of them properly. And still sound better than expensive, overpriced headphone amps.

 

[Argybargy]

Try reversing the AC plug and see if some of the noise goes away.

The bass will probably quicken and tighten after you replace the main filter caps.

 

[duncan1]

Frank2908- Its news to me that step down transformers-with STANDARD -mains input winding and STANDARD mains output winding are noisy. If so lots of manufacturers would be out of business and millions of people using them would have a problem.
                 But remember there there are DIFFERENT takes on step-down transformers-all are not equal.
                     I have in my house a 30KW -1/1 isolating transformer bought from a major electronics test gear company used on one of their assembly lines to power test equipment that tested their test equipment that was manufactured . You can imagine they wouldnt live for a second with  a "noisy" transformer.
                      Step-down transformers of any quality have to come up to spec. of the laws of the country they are sold in -As we are dealing in high voltages- low insualtion resulting in death could cost that company millions.
                         The exception here is AUTO -step down transformers -these as the name suggests have only ONE winding -tapped down at various levels- These are DANGEROUS and must be sold ONLY in an EARTHED container as they are indirect contact with the mains. If found otherwise then -report to authorities- If I sound strict its because I know people who have died from them.
                             So normal step-downs are not noisy.
                                  Unless CONTAINING _electrolytic filters that could be OLD.
                                     Next post is a point on earths. 

 

[duncan1]

A lot of time is spent  talking about earth returns and yes there should be only ONE earth loop.
                    BUT here we are talking about EQUIPMENT earth[from one unit to another]
                           It may NOT have struck some people but MAINS earths are VERY noisy with HF / LF noise /distortion.             While I am not suggesting/approving that you do this -and take NO responsibility for any mishaps.
                               If your equipment is VERY sensitive  then you could run it without an earth- YES I know -bad advice.                         BUT it will reduce your noise floor a bit- Taking into account you already have NO problems with earth loops.  For those with a garden run an heavy copper earth wire into the garden attach it to a copper spike and bury it vertically at least 3FT down in the soil and make sure the ground isn't always dry.
                                     Your earth then will be superior to the electric company.
                                        I also realize that in the US some electric companies use only a live wire and the negative is connected to ground   But that is up to you to try as I live in the UK which has a negative return[which eventually goes to earth] .I have been running mine for years without  an earth with no problem.
                                       There again I have a high body resistance to high voltage otherwise I would have died long ago.-Lived through 240V AC/600V  DC and yes several from working on the -727-11. 
                                          If you have fine moist skin- do not take any  chances!
                                            You can check your body resistance with a meter-dry your hands first! 

 

[Silent One]

"The Forecast"
 
When I get my hands on that G-22000 again, the forecast may call for some 

 Heavy Weather. I'm gonna put the amp through its paces and hit it with a wide variety of tracks from Weather Report... can't wait!

 

[PhoenixG]

The last parts came in today for my pioneer HPM-150's. They were included as a throwaway from the guy I got my SX-1980 from. The woofers were missing and a tweeter was blown out. Essentially they were only half complete. I know it's a sacrilege to talk about speakers on a headphone page, but I have to say one thing - it is clear why these items were originally bought together. The sound is flawless. Clear highs and mid, full bass. I can't turn them up more than 1/4th of the way to their rated power and stay in the same room.
 
I was going to sell them, but I think I will keep them and sell something else instead now, haha. 
 
I have the same setup as this guy 
Pioneer somehow still makes the woofers, so I got a little lucky.

 

[Oregonian]

The last parts came in today for my pioneer HPM-150's. They were included as a throwaway from the guy I got my SX-1980 from. The woofers were missing and a tweeter was blown out. Essentially they were only half complete. I know it's a sacrilege to talk about speakers on a headphone page, but I have to say one thing - it is clear why these items were originally bought together. The sound is flawless. Clear highs and mid, full bass. I can't turn them up more than 1/4th of the way to their rated power and stay in the same room.

I was going to sell them, but I think I will keep them and sell something else instead now, haha. 

I have the same setup as this guy 


Pioneer somehow still makes the woofers, so I got a little lucky.

I can relate. I just bought a "semi vintage" (early 90's) Yamaha receiver and NS-4 speakers as a pair for very cheap, and the sound of those old speakers is phenomenal! Real sweet sound and clarity beyond belief.

 

[DefQon]

Sounds about right. I'd recommend taking it to a vintage shop to get it cleaned up and some parts replaced. Or, if you're a DIY'er, just do it yourself. Buy some Deoxit, canned air, and a cheap toothbrush, and clean the boards carefully. These things'll last forever if you take care of them properly. And still sound better than expensive, overpriced headphone amps.

can service it myself if something goes wrong but seriously was blown away by the quality parts used in a 20+ year old amp. No leaks nothing the ElNA Silmics in there should last another 5 years easy but I do plan on a few mods up my sleeve as well as recapping the standard ELNA audio caps in the amp.

 

[Skylab]

PhoenixG that is one SWEET setup!!!

 

[vid]

 
Posted this in another thread, but this thread might be more apt in this case.
 
Anyone recognize the above pattern of harmonic distortion (the 3rd basically looks like an offset copy of the 2nd) and what might potentially cause it? The plot is of headphones driven from the phone out of an '80s integrated amp. When measured out of another amp, the distortion plot for those phones looks more agreeable, i.e. 3rd is lower than 2nd and the two don't look identical.

 

[duncan1]

                   The higher distortion is exactly at the frequency of the human ear that it is most sensitive to.
                       Which isnt good. \even a valve amp usually has those peak frequencies at a lower level.
                             If SS then check the bias current at the output--may be underbiased- or the coupling caps need replaced/ input cap  IF electrolytic. 
                                 There are other  things it could be but thats a start.
                                          Have you got a link to circuit diagram?

 

[vid]

If by bias current you mean the DC offset, it checked out ok about six months ago (-3.2/-9.5 mV). I'm not sure if the sound problem existed back then or not - I'll see about remeasuring the offset this evening.
 
The thing is, the distortion problem seems to only occur if I have the input into CD/AUX - and even then this problem only started late last year or so and that input worked fine until then. TUNER and TAPE/EXT still give good sound; the graph below was measured with the same phones having the source plugged into TAPE.
 

 
That's about how they measure from a modern headphone amp as well, so it should indicate that there's no problem. Plugging the input back into CD/AUX still gives high distortion figures.
 
There's a service manual for this model at http://hifiengine.com/library/technics/su-300.shtml. I've looked over the diagrams a few times but to me it just seems like CD/AUX goes into the same place as e.g. TAPE/EXT. So maybe the input itself is having problems and not so much the amp?

 

[tribestros]

Need some help guys.
 
Marantz 2252b on a Panamax MR4000.
 
A light hum that doesn't change based on the volume, but only with headphones.
 
Thought it was a ground loop. Definitely not.
 
Still sounds great, but this is a little annoying.