Topic: Surplus amps

[wanderlust]

i agree, i really am quite unfamiliar with that model, infos will only just be figures, if youll like the sound then no matter how un exciting would be the info you have gathered on it, it really wouldnt matter, now on the otherhand kahit ba mapaka impressive yong specs e d mo naman gust o tunog wala rin yon. let your ears decide bro.

i dont think its normal, as far as i know, the only audible sound youll hear when turning on an amp is the minimal click, not a pop-up.

[markygail]

sakin din yung konzert AV500R ko nagkakaron ng pop sound everytime i turned it on. ang ginawa ko kanina dinisconnect ko yung lahat ng speakers sa binding post except for the fronts. nawala yung pop sound. ano kaya yung problem nun? help din po mga sir....

[sandawa]

i've decided to post what happened to me today, which is comparatively "malas." anyway, it could provide some lessons especially to newbies who are now into surplus hifi.

i picked up a used Yamaha B-4 power amp yesterday for P5K and had it opened for inspection and cleanup just this morning. problems emerged after the cleanup: two of three indicator lamps were dead thus had to run to an electronic shop for two 12-volt lamps. a lamp costs P10 to P12 each. i installed the lamps and everything looked okay until i noticed one channel was silent.

made some connector changes until i found it was the right channel of the Tono preamp. a resistor was disconnected from the common/ground post due to a loose female RCA. that twisted the resistor tail resulting from frequent cable switching. i soldered the resistor back and tested again. still, no sound on one channel despite a new round of cable switches. then, i found how stupid i was. one spade on the speaker terminal was pulled out probably while disabling some connectors on the power amp.

that robbed me at least three hours but it's still okay. sometimes, quirks like this make this hobby much more interesting. the bottom line for the newbies: don't get scared when problems like this crop up - this should be expected for getting into surplus hifi. it's part of the fun. learn to use the soldering iron, and be aware of basic parts to replace, and how much these cost. you'd save a lot that way than depending on technicians that could charge you a lot of money for just replacing a fuse.

"parang may bagong kabayong sumisipa sa kuwarto mo ngayon ah. mukhang may binili ka na namang JBL diyan, o Sansui kaya?" may wife commented. "hindi, nag-modify lang ako ng amp ko, may natutunan kasi ako sa PinoyDVD website," i replied. "akala ko may binili ka naman, just to remind you 2nd sem enrolment na first week of November," she said. aray! that's equivalent 6 to 10 good surplus amps.

Yamaha B-4 was mean, rated at about 120wpc (B class) and 40wpc (A class), the company said it produces double that power due to its "X-power source circuitry" whatever that means. i let my ears be the judge though. it's a lot more powerful than my "good-looking" B-3 amp, or even my sweet sounding Accuphase, and approximates the sheer power of ther Sansui Alpha 907 (160wpc).

[kid]

sandawa,

i also encounter that problem when i bought a suplus tuner. after a week of use, the light bulb of the LCD was busted. when i opened the case i saw a replacement bulb and thought that it was thrown away by the owner due to that problem then i started to heat up my soldering iron and replaced the lead.

[Chito C.]

Guys,

Saw this at cubao (beside mrt station besid4e farmers market) for your info,

Yamaha A-7 (2 units)
Aurex SB-630
Sansui - AU-607
Onkyo Integra A-733 and A-817D
Techbics SU-V7A
Sony F33ES
Kenwood KA-990D
Denon PMA-940
Marantz PM64

Asked for the selling price as usual aanga anga yung mga nagbababntay. Also saw  a Kenwood Cpd dp-7x and lots of big speakers. Didn't test any.

[H a n $]

Chito,

Any cdp models available??

[Chito C.]

kenwood dp-7x lang nakita ko

[H a n $]

chito,

Thanks.. wala na pala yun shop near Isetann according to BGA..

[Chito C.]

chito,

Thanks.. wala na pala yun shop near Isetann according to BGA..

Meron pa dun. I was there last week madami ding cpd's basta lakarin nyo lang yung aurora isettan going to mercury drug lagpas pa sa mga ukay ukay.

[JojoD818]

sandawa,

that's the diy spirit! keep it up sir! 

[taruc]

mga sir, tanong lang. mag kano kaya price nitong Harman Kardon  PA 5800 (5chn) 400watts amplifier na used lang? thanx...

[relay_70]

after long research in the forums, i finally bought this surplus amplifier.... ONKYO Integra a-817xd
hanep ang tunog! swabeng swabe, i can listen to this for hours without headache! kaso sa typical sony ref style speaker ko palang nasubok... i dont know kung ok ang tunog nito sa target kong speaker which is wharf 8.1... ok rin po ba sa 8.3 to?

btw im into music listening so dun sa mga nakasubok na ng 8.1 and 8.3 i need your comments... pls.. if ever kayanin ng budget eh pwede po kaya ang monitor audio b2 dito?

one more thing, talaga po bang hindi umiilaw yung servo operation LED ng ONKYO... di ko rin kasi alam kung para saan yung indicator na yun....

hirap talaga ng newbie... heheh!

[RU9]

Hi sandawa,

Talking about the Tono preamp improving the sound of surplus amps. I recently tried to connect Tono preamp to the equalizer connections of my Pioneer int amp. I think Iceman mentioned this before but using an AVR.

Int amp equalizer out --> Tono preamp in
Tono preamp out        --> Int amp equalizer in

This is a far better connection. Now I can play LOUD without the music being muddy.

Louie



This is a better connection

   

[aHobbit]

Hi sandawa,

Talking about the Tono preamp improving the sound of surplus amps. I recently tried to connect Tono preamp to the equalizer connections of my Pioneer int amp. I think Iceman mentioned this before but using an AVR.

Int amp equalizer out --> Tono preamp in
Tono preamp out        --> Int amp equalizer in

This is a far better connection. Now I can play LOUD without the music being muddy.

Louie



This is a better connection

   

For an integrated amps that has no external connector between pre-amp and power-amp, this is indeed the cleaner way of enjoying the tono pre-amp - (now functioning as an "equalizer"  ).

For those amp that has the external connector, the ideal connection is still the tono pre-amp to the power-amp-in. The pre-amp of the integrated amp will become idle in this sense. This makes less stages for the music - theoretically cleaner.

Of course, it might be different for other people who is still not satisfied with the sound the latter setup produce. The earlier setup has another distortion component added (being three stages already) - but who cares if the sound can be appreciated anyway.

[Titanium]

after long research in the forums, i finally bought this surplus amplifier.... ONKYO Integra a-817xd
hanep ang tunog! swabeng swabe, i can listen to this for hours without headache! kaso sa typical sony ref style speaker ko palang nasubok... i dont know kung ok ang tunog nito sa target kong speaker which is wharf 8.1... ok rin po ba sa 8.3 to?

Bro, saan at how much mo nabili ang integra. I am planning to buy one and I need to compare prices.  May main -in at pre-out ba? . Thanks.

[RU9]

For those amp that has the external connector, the ideal connection is still the tono pre-amp to the power-amp-in.

I have this set-up, Tono Preamp to a Rotel RB-03 amp.  At 9:30 Tono vol. setting, distortion is already present.  A component mismatch according to Rene.

Also tried Tono preamp to CD-IN of Pioneer Int amp as suggested by early users of the Tono.  Sounds impressive but fatiguing and boxy sounding in the long run.

[sandawa]

i have a problem with Tono pre-amp being hooked as an equalizer, which it is not. connecting it in between an active pre-amp and power amp of a surplus amp could render it useless although it could solve volume control problems for some setups.
what would happen is you'll be feeding Tono with the signal coming from the built in pre-amp of your surplus unit. it could even degrade the sound coming out.

assuming Tono is superior than the built in pre-amp of the surplus amp:
a.) built in pre-amp of surplus unit reduces fidelity coming from the source by 2%
b.) Tono reduces fidelity by 1%

that setup would technically reduce sonic quality beyond 2%, whereas the reduction would only be 2% if the built in pre-amp is used (without any other equipment on the loop) and only 1% (best setup) if the Tono is used with the power-amp.

aHobitt is right on the ideal setup, which is using Tono straight to the power amp.  for surplus amps, this means using the switch at the back of the unit and connecting Tono to the power amp jacks.

but then again, if the sound coming out of that setup is okay with you, don't let this opinion bring you down. let your ears be the judge.

[wanderlust]

i am a tono + ss user also, and i have the tendency to agree with sir sandawas observation, however i do not limit my connections to the main outs alone, had tried cd direct, cd, aux, etc..... in the search for the best connection for my set-up....  eventually it all boils down to what your preference, after all it is you that listen to your systm all through out.

[aHobbit]

Obviously, RU9 used his ears! 

And it is probably mismatching (of tono-out and power-amp-in) which can cause some fatigue-causing listening strain. I could have brought this matching thing up in my previous post, but decided to avoid more complicated discussion.

As I said, the ideal connection is "theoretically" recommendable. It is entirely different thing to hear it for yourself.

I agree with some "audiophiles" that sometimes, it is the distortion that we run after. Who would not want to hear very beautiful music from bad recordings?

Distortions may sometimes be the magic to make something listenable. Or should I say good distortions. 

Let's give our ears a break - decide the listenable - and enjoy the music. 

[sandawa]

i would agree. i just got a surplus Onkyo preamp, containing up to 5 kilos of filtering electronic components, which makes bad recordings listenable. outside of that, i've been consistent in my belief that sonic preference is something personal that couldn't be dictated by anybody, not even by so-called audiophiles.

a drunk prize-winning playright and poet once yelled at me during a drinking session at Trellis: "I don't care care if the music is coming from a transistor radio or from your expensive hifi system. All I wanted to hear was Paul Simon's guitar."

[nerveblocker]

Hi!  I did a set-up with my friend who had a pair of 8 ohm bookshelf speakers in his sala and a pair of 8 ohm cube speakers in his foyer all connected to the Speaker A and Speaker B inputs of his Marantz surplus amp.  After 3 songs running both speaker A and B, the amp was really hot.  Fearing that it would break down and thought there was a problem with the amp, I replaced it with a Sansui surplus stereo amp and connected them speakers to the amp.  There were no problems for 4 days until suddenly the amp just shut down and no way can it be turned on again.  I ran through the system and didn't find anything wrong like a possibility of a short or something. 

Possible problems:

1. AVR- amp is connected to a 1000W AVR in 110 volts.  This is a brand new AVR...possible uncontrolled voltage in the AVR(?).  Jap amps need to be plugged in 100V as said in the back of the amp.  Would this cause the problem?

2. Speakers- 2 way bookshelf 120 watts 8 ohms, cube speakers 60 watts 8 ohms both running as speaker A + B.  My Jap friend told me that it is ok to run speaker A or speaker B but not Speaker A + B.  It might have caused the problems of the amp.  Is this true?

3. Amp- 2 amps bogging down in the same set-up(?)  I am now using my Luxman stereo amp in 220 volts.  Fearing it might follow on the same fate.  Hmmm.....

Need help gurus...anyone?

Thanks in advance!

[akyatbundok]

doc, i think running both speakers A and B at the same time means that you are running 2 speakers in parallel,  which lowers the impedance load down to 4 ohms (possibly lower) and therefore the current demand on the amp is increased..... that's probably why at the back of the amp they suggest 16 ohm speakers when connecting both A + B so that the total speaker load is still 8 ohms..... with two 8 ohm loads in parallel, and each speaker probably going down to 4 ohms on bass passages, you get an average load of 4 ohms and occassional dips down to 2 ohms, which can be considered unsafe for an amp rated for 8 ohms nominal.

[sandawa]

i fully agree with Sir Akyat. using 2 pairs of speakers is risky especially if you're using the amp longer than usual and at higher-than-normal volume. impedance is not constant and even speakers rated at 8 ohms could eventually go down to 6 ohms, or less, on low-frequency passages. with 2 pairs of speakers, the impedance rating dives to 2 or 3.

that's the reason why some amps have 2 ohm ratings since these were made to remain stable below 4 ohms and could be used for commercial applications. many audiophile power amps though accept only one pair of speakers. i believe your Sansui has been damaged, it's prone to problems like that. getting too hot, however, does not necessarily mean something is wrong, since class A amps are designed that way.

[aHobbit]

Hi!  I did a set-up with my friend who had a pair of 8 ohm bookshelf speakers in his sala and a pair of 8 ohm cube speakers in his foyer all connected to the Speaker A and Speaker B inputs of his Marantz surplus amp.  After 3 songs running both speaker A and B, the amp was really hot.  Fearing that it would break down and thought there was a problem with the amp, I replaced it with a Sansui surplus stereo amp and connected them speakers to the amp.  There were no problems for 4 days until suddenly the amp just shut down and no way can it be turned on again.  I ran through the system and didn't find anything wrong like a possibility of a short or something. 

Possible problems:

1. AVR- amp is connected to a 1000W AVR in 110 volts.  This is a brand new AVR...possible uncontrolled voltage in the AVR(?).  Jap amps need to be plugged in 100V as said in the back of the amp.  Would this cause the problem?

2. Speakers- 2 way bookshelf 120 watts 8 ohms, cube speakers 60 watts 8 ohms both running as speaker A + B.  My Jap friend told me that it is ok to run speaker A or speaker B but not Speaker A + B.  It might have caused the problems of the amp.  Is this true?

3. Amp- 2 amps bogging down in the same set-up(?)  I am now using my Luxman stereo amp in 220 volts.  Fearing it might follow on the same fate.  Hmmm.....

Need help gurus...anyone?

Thanks in advance!

There are conditions when you can use A+B speakers - that is, you have to somehow control the volume of the amp in such a way that your amp will not overload - and this you will note by the heat the amp produced.

You did not mention model of the Sansui amp. I have some of these models, and it can detect shorts or overload and can shut the whole system or just a channel, and will activate it again after powering it off and then on again.

You may also check primary and/or secondary fuses inside the amps.

[nerveblocker]

akyatbundok, sandawa, aHobbit-  Thanks guys for your inputs.  I have to check then if we can make the speakers 16 ohms to refrain from damaging the amp.  2 amps busted...gastos!  I have to warn my friend using my Luxman amp.  Ok lang for the Marantz and the Sansui to burn out...please not the Luxman.... :'(

[sandawa]

in such cases you can still save your amps and could mean replacing just a couple of fried transistors. spare parts cost should be from P500 to P1K per amp if sourced from Raon. i have used more than half a dozen Sansui amps already, and currently have AUD-907F and Alpha 907 but never had such problem even if i sometimes use four speakers simultaneously. but in the '80s and '90s, even Sansui's service center at VV Soliven admitted A and R amp/receiver series (Sansui models starting with those letters) frequently suffer from that problem. happy listening, Luxman is quite good in making amps.

[wanderlust]

i see  the sansui as a very reliable amp, i personally own a 907, and have abused it quite alot, i even triggered the protector mode to be activated (i havent really figured out why, maybe one of the speakers was out of phase) a couple of days ago but thats just it, after i turned it on again its up and running  n namn.... quite a sturddy amp i say. heat is always at tolrable level though when in operation even if left playing the whole day tru....

i also opened it and took several pics of its innards, most part were premuims as i see it, will post the pics soon.

[av_phile1]

but in the '80s and '90s, even Sansui's service center at VV Soliven admitted A and R amp/receiver series (Sansui models starting with those letters) frequently suffer from that problem. 

I think these are the sansui receivers/amps that featured their superfeedforward designs.

[aHobbit]

I think these are the sansui receivers/amps that featured their superfeedforward designs.

I think not. Most of their integrated amps starts with A (as in AU) and perhaps the receiver starts with R.
The fact is that the later '70s and 80s international models are not manufactured as good as the Japan local counter models.

But if you got something surplus from japan, wnderplus is correct in saying they are built well.

Of course, it is entirely different issue if the pier guys already make some repair work in the said unit.

I have one 607XDecade, fed with 2-8ohm (4-ohm equivalent) per channel and power a big open hall at musical performance level with audience of about 200. Some people commented we have indeed good-sounding powerful sound gears.  No busted thing. Powerful sound gear at 4000 only.

At one time, a channel do not have a sound. A check reveals a short circuit on the speaker side. Fix the short at speaker side, put off the 607XD, and power it up again. Case closed. 

[sandawa]

Most of their integrated amps starts with A (as in AU) and perhaps the receiver starts with R.
The fact is that the later '70s and 80s international models are not manufactured as good as the Japan local counter models.

The Sansui amps sold here back in 80s and 90s as brand new units start with A not AUD, AU or Alpha, such as A50, A60, A80 etc. Yes, these are international models that are inferior in built and were mostly released as components to systems. The receivers sold locally also start with R as in R5, R7, R80, etc. These were the models with tin covers at the back.

Sansui's good quality amp models in Japan start with AUD but almost always 07 as last numbers, with 907 as top of the commercial line. It was also AUD in the US, except they do not end with 07. Quality of those released in US suffered when the yen strengthened against the dollar starting in the mid '80s. Sansui's high quality receivers start with G and Z and not R. The Rs were the cheapos.

My two 907s and about half a dozen other AUDs in last 20 years also use super-feedforward technology but I never had the problem with them. The relay system in these amps work and all you have to do is switch on and off your unit but if it doesn't work anymore, burn-out likely occured due probably to shorted speaker wires and diving impedance below 4 ohms.