Topic: Surplus amps

[dana]

At last, after a long search - My first Sansui... 
AU-alpha777DG
Excellent condition, 100v but not surplus, built-in DAC, with Original remote control
Rated at 90wpc at 8 ohms, weighs 18.2kg

.....

WOW, CONGRATS.
ANOTHER BEAUTIFUL TOY!
DUMADAMI NA YAN, AH

[oweidah]

I have a Harman Kardon receiver model 730 which I bought from a friend years ago. sold then bought back finding it in fine condition as it was b4 i sold it.

I dont think its a surplus but this forum is turning out to be where you could discuss vintage equips.

Anyone know anything about this receiver?

*  http://pinoydvd.com/board/index.php?topic=51520.0


*  for info on hk730 - >
http://www.harmankardon.com/product_support/support_detail.aspx?Region=USA&Country=US&Language=ENG&cat=&prod=HK730&sjump=ps&#active

[markmlists]

In searching for surplus amp info on the net, I found confusing information about an amp being " Dual Mono"

In some readings "Dual Mono" means 2 transformers and in some, having 1 big transformer as long as there are separate windings for left and right channels is also considered as dual mono.

Denon PMA-850 and PMA-830 is said to be dual Mono despite having 1 big transformer.

Author/Reviewer said it here:

 http://www.hi-fiworld.co.uk/hfw/oldeworldehtml/denonpma850.html

Sansui AU-9500 is also said to be dual mono from their 1973 official brochure with only one transformer.

Copy of the original brochure here:

http://www.classicsansui.net/Integrated%20Amplifiers.htm


VERSUS

Pioneer SA-8800II A-717 Dual transformers- naturally dual mono.

So, does this mean an amp does not need to have 2 transformers to be considered dual mono?

Your thoughts please.

[rascal101]

Dual mono means 2 separate transformers. One each for the Left and Right channel.

Brochures are are not necessarily 100% true. I believe this things come with the disclaimer "specifications subject to change without prior notice" - which is similar to "engineering reserves the right to change things depending on customer feedback or management feedback". Sometimes, the upper guys want to make a pitch - an upgrade or downgrade depending upon their mood. I think the brochure came out first before engineering made the changes.

[Reymer]

I think Dual Mono refers to amps with 2 identical, separate circuit modules for the left and right channels. I once had a NAD 214 Power amp and it is also described in HiFi Choice as Dual Mono, and it only has 1 big toroidal transformer in the middle.

[markmlists]

Thanks Rascal and Reymer.

Reymer, actually yan din sabi sa review site about the Denon PMA850, because separate windings for each channel daw..

[rascal101]

Separate windings for each channel pero using on the same core = dual mono???

Wala akong magagawa kung iyun ang definition nila. Ngayon kung maraming ganito ginagawa then accepted siguro ng industry. Ang tanong, ilang pa bang kumpanya ganito ginagawa?

[Reymer]

Separate windings for each channel pero using on the same core = dual mono???

Wala akong magagawa kung iyun ang definition nila. Ngayon kung maraming ganito ginagawa then accepted siguro ng industry. Ang tanong, ilang pa bang kumpanya ganito ginagawa?

Bro, ive seen many amps na ganito ang construction, only 1 big power transformer for 2 channels. (even an Aragon 4004 ). Maybe this is the reason why some (those with deep pockets  ) opt for monoblocks.

[southpeak]

Bro, ive seen many amps na ganito ang construction, only 1 big power transformer for 2 channels. (even an Aragon 4004 ). Maybe this is the reason why some (those with deep pockets  ) opt for monoblocks.

by your leave sir Reymer. the aragon 4004 has two separate, identical transformer. maybe you were referring to the 2004. lifted from "Classic Aragon
amps - A Primer"
"The first Aragon amplifier products were the 4004, and it's little brother the 2004.  The 4004/2004's electrical design was widely reported to be the work of Dan D'Agostino of Krell.  Mr. D'Agostino was credited in various magazines as being responsible for 1) Circuit design of the early Aragon components; 2) Parts selection; and 3) Development of the Quality Assurance program for Mondial Designs.  This may--or may not--be true, but it is NOT confirmed by Mondial or Klipsch.  The Industrial Design (the way the product looks, and to some extent, the internal parts layout) is the work of Robbii Wessen, as evidenced by the name "Robbii" silkscreened on the back panels.  Robbii performed the industrial design for the Aragon and Acurus product line up until the Klipsch takeover.  The 4004 and 2004 share chassis and general layout--the front panels are a flat plate, and the top and sides are formed from a single sheet of steel, perforated over the internal heat sinks which are below the famous "V" notch on the top.  The 2004 uses fewer output transistors, and a single, dual-wound transformer while the 4004 has two transformers.   The 4004 was named because it could output 400 watts into a 4-ohm load, thus 400-4 which became 4004.  The 2004 is rated at exactly half the output of the 4004, 100 watts into 8 ohms, 200 into 4 ohms.  Don't be fooled, the power supply of either amp is quite huge in relation to it's rated output.  The output transistors are individually tested and matched.  There are 8 output transistors per channel on the 4004, four for the positive side of the waveform, and four for the negative side.  Each group of four transistors will be matched.  Same goes for the 2004, except half as many transistors are used.  The output transistors are metal case units"

http://reviews.ebay.com/Classic-Aragon-Amps-A-primer_W0QQugidZ10000000001149810

Aragon 4004 MkII
 

magkapatong lang sir 

[Reymer]

Sorry, 2004 nga pala  . I stand corrected. Thanks Southpeak.

[dana]

by your leave sir Reymer. the aragon 4004 has two separate, identical transformer. maybe you were referring to the 2004. lifted from "Classic Aragon
amps - A Primer"

Classic Aragon....=ORAGON MAN TALAGA!...MAGAYON PA!  (bicolano quote...)

[av_phile1]

Separate windings for each channel pero using on the same core = dual mono???

Wala akong magagawa kung iyun ang definition nila. Ngayon kung maraming ganito ginagawa then accepted siguro ng industry. Ang tanong, ilang pa bang kumpanya ganito ginagawa?

Strictly speaking dual mono means separate power trannies, power supplies and separate circuits.  The only thing common is the power switch and the chassis and the power chord.  The Aragon 4004 pictured above can claim true dual mono classification.  I think this is what makes the Aragon more expensive than the Acurus line, among other things ofcourse.  I am not aware of any dual mono Acurus stereo amp, at least the newer ones before the Klipsch takeover. 

But I guess in the interest of saving space, you can have separate transformer windings sharing the same core instead and still claim dual mono. 

[rascal101]

Definitely there will be 2 separate layers for left and right channel. The one closest to the core will definitely have lower parasitics.

If it was me, I'd rather have one winding for mains supply which I believe most manufacturers opt. You can use the available space for auxiliary supply. Why bother with 2 separate windings - 1 ea for left and right channel. Thermals will definitely be higher + additional process and cost.

[markmlists]

I have just learned that Edrel Sison customizes stepdown transformers with 100V output for use with Surplus Amps. Japanese amp enthusiasts can pm him.

[docsialu]

hi gud pm,

some body is selling me a vintage luxman L-504, is this any good? i need ur reviews guys, tnx

[ATJr.]

dual mono = stereo, semantics.....

[dana]

I have just learned that Edrel Sison customizes stepdown transformers with 100V output for use with Surplus Amps. Japanese amp enthusiasts can pm him.

Yes,Edrel makes them. He can even make you a transformer with 100 & 110 volts output with built in primary switch (fuse protected), which makes it more convenient.

Calling all pier surplus owners (amplifiers,refs,& aircons) , you can pm Edrel Sison, a pdvd member.

[qguy]

why not just rewind the internal transformer, should be cheaper and you no longer need the stepdown transformer

Yes,Edrel makes them. He can even make you a transformer with 100 & 110 volts output with built in primary switch (fuse protected), which makes it more convenient.

Calling all pier surplus owners (amplifiers,refs,& aircons) , you can pm Edrel Sison, a pdvd member.

[qguy]

Hi What is the US version of this model (Sansui AuD 907 Decade)

[bumblebee]

I believe only series' 7 and below have international counterparts. The 9's were for the domestic (Japanese) market.

[sandawa]

Look here for Sansui's domestic and international model equivalents:

http://www.sansui.us/Issues_IntvsDomestic.htm

[qguy]

thanks for the info, apparently there is no US version for this amplifier, anyone knows the specs ? Any reviews?  I just saw that its a 160 wpc ?

Look here for Sansui's domestic and international model equivalents:

http://www.sansui.us/Issues_IntvsDomestic.htm

[rascal101]

From http://page.freett.com/knisi/sansui07.htm

SANSUI AU-D907X DECADE

* POWER AMPLIFIER SECTION *

Effective output:
    190W + 190W (10Hz - 20kHz, 6 Ω) 
    160W + 160W (10Hz - 20kHz, 8 Ω)

Total height harmonic wave distortion factor:
    0.003% or less (from 10Hz - 20kHz and 8 Ω effective output)

Frequency characteristic:
    DC - 300kHz (+ 0 dB, - 3 dB)

Slew late:
    ± 300V/μ s (6 Ω)

Rise time:
    0.5 μ S

 
* PRE-AMPLIFIER SECTION *

PHONO maximum permissible input (1kHz and THD 0.01%):
    (MM) 300mV 
    (MC) 35mV (Trans HIGH)

Signal-noise ratio  (A network, short circuit):
    90 dB (PHONO MM) 
    80 dB (PHONO MC) 
    110 dB (CD, TUNER and TAPE)


OVER-ALL

Rated electric power consumption:
    370W

Size:
    466 (W) × 161 (H) × 431 (D) mm

Weight:
    26. 0kg

[southpeak]

thanks for the info, apparently there is no US version for this amplifier, anyone knows the specs ? Any reviews?  I just saw that its a 160 wpc ?

sir qguy, babelfish english description/review as below...
if you are getting one of this then congratulation in advance.. 

http://babelfish.altavista.com/babelfish/trurl_pagecontent?lp=ja_en&trurl=http%3a%2f%2fhomepage2.nifty.com%2f2001odakun0801%2fsubdtest6au.html

[Lord Foo]

I'm wating with bated breath if its an acquisition or just curiousity. I hope its an acquisition.

[qguy]

Just curious lang 

I'm wating with bated breath if its an acquisition or just curiousity. I hope its an acquisition.

[ATJr.]

why not just rewind the internal transformer, should be cheaper and you no longer need the stepdown transformer

this totaly makes sense...gets murphy out of the way too....

[qguy]

Specs seems impressive, but how good is this amp ?

I'm wating with bated breath if its an acquisition or just curiousity. I hope its an acquisition.

[rascal101]

Paging Sir Mandrake ... reviews for AU-D907X DECADE

[docsialu]

Gud pm,

hi guys, i need some input regarding luxman L-504, what do you think about this amp?

tnx you