Quad 50e

June 19, 2019, 2:37 am

Hi members.
I would like to ask if any members can tell me the primary winding specifications of the Quad 50e output transformer. I will be grateful for your help and thank you in advance.
Regards Western 91.

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Hypex PSC.400 Bridging

June 19, 2019, 2:59 am

≫ Next: Luxman L-2 power supply

≪ Previous: Quad 50e

To bridge or not to bridge that is the question. I am using a Hypex PSC2.400 for the bass bins of Klipschhorns. the woofers are 4 ohms outside the box but act like 8 ohms in the box. Given the woofers impedance should the Hypex PSC2.400 be run in bridge or non-bridge mode? These speakers are very efficient at 104db 1w/1m so I don't really need the extra power.

What do you think?

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Luxman L-2 power supply

June 19, 2019, 3:14 am

≫ Next: Hello, I'm new, thanks for letting me join and a question

≪ Previous: Hypex PSC.400 Bridging

Hello,
I've a "new" (for me) Luxman L-2 power amp.
The label on the back says 220V.
The transformer is the P2348 and it's primary is wired like this :
Brown Neutral
Orange Live
Red unplugged.
According to the schematics, my transformer should have a blue and a black wires on the primary, and be for 120V.
My mains is at 240V so :
1: Do you think there is a typo on the schematics ?
2) Should I unsolder the orange wire and replace it by the red one for 240 V ?
3) How could I know if I have a 240 V winding between the brown and red wires ?
Many thanks in advance for your help and advice !
Best regards.
P.S. : I've not, yet, powered the "device" ;-)

Attached Files

Luxman L-2 Service Manual - schema - 200dpi.pdf (62.0 KB)

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Hello, I'm new, thanks for letting me join and a question

June 19, 2019, 3:24 am

≫ Next: TLE2426 -- noisy?

≪ Previous: Luxman L-2 power supply

Hi, my name is Julian Robinson, I'm a fairly recently retired professional viola player (39 years with the CBSO) from Birmingham UK. I have always had an interest in Hi Fi from a teenager, now I have more time to pursue it. Current set up -
Rega RP3, Goldring 1042, various Quad amps and an FM2, Quad 57's and 63's plus Cambridge Audio CXN and CXC and lots of other bits and pieces.
I have a Goldring GL75 which I'm hoping to rebuild, I've signed up to "Lenco Heaven" for that but I also have a pair of Monitor Audio MA4's which I've owned since the early eighties. I've found a place to rebuild the bass/midrange units

AudioLoudspeakers

and the tweeters seem fine but I'm guessing the crossovers would benefit from new caps. My question therefore, is - does anyone have a circuit diagram? I don't own a capacitance meter and I dont really want to spend £100 + on an accurate one which I won't use much. I could reverse engineer the circuit but the capacitor values are not all readable anymore.
Many thanks in advance,
Julian

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TLE2426 -- noisy?

June 19, 2019, 5:57 am

≫ Next: Fostex FE206E

≪ Previous: Hello, I'm new, thanks for letting me join and a question

TLE2426 specs put noise at 120uV 10Hz to 10kHz, (30uV with the noise reduction option). Is the device too noisy to be used to inject positive bias into the non-inverting input of a single supply opamp circuit?

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Fostex FE206E

June 19, 2019, 10:09 am

≫ Next: CT scan analysis of various DAC chips

≪ Previous: TLE2426 -- noisy?

Got my fe206es up for sale, check them out!

Fostex FE206E Full Range Speaker Pair | eBay

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CT scan analysis of various DAC chips

June 19, 2019, 10:11 am

≫ Next: FS Hypex SMPS

≪ Previous: Fostex FE206E

Hello fellows,

I'll have the possibilites to access a CT scan at a local research facility. The CT is said to offer details in the 0.000001m range.

One scan run takes about 45min, in total I'll have about 3h access to the scanner.

Already set are scans of:
- a defective TDA1541A
- defective/faked AD1862
- re-labeled PCM58

In my inventory I further have:
- PCM69
- PCM67
- PCM1794a
- AD1865
- AD1955
- CS4328 (my personal favorite)
- TDA1540
- TDA1387
- TDA1305
- various digital filter ICs (DF1706, SM5813, SM5842, YSF210, YM3434

There is one requirement that I was ordered to: To describe the test objectives....
I thought I can argue about the defective parts (identify the failure mode) and the old-school "hybrid", e.g. Bipolar/CMOS/CrNi parts.
I have no real arguments about the latter standard-CMOS parts, so maybe one of you fellows have some input...

Cheers, Markus

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FS Hypex SMPS

June 19, 2019, 10:52 am

≫ Next: Blameless style lateral MOSFET amp

≪ Previous: CT scan analysis of various DAC chips

I have two pcs hypex smps 1200 400 power supply
1pcs for $100
2pcs for $180
+ shipping and paypal fee
all are good condition .

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Blameless style lateral MOSFET amp

June 19, 2019, 11:35 am

≫ Next: Power Amplifier AB class

≪ Previous: FS Hypex SMPS

I took the basic Hitachi MOSFET circuit and added various improvements from the Doug Self "Blameless" approach. Output inclusive compensation was one notable idea I thought would help push up the loop bandwidth and make up for MOSFET output non-linearities.

The results seem encouraging:

Code:

1 kHz, upto 20 harmonics

========================



Fourier components of V(output)

DC component:-0.0651619



Harmonic    Frequency     Fourier     Normalized     Phase      Normalized

 Number       [Hz]       Component     Component    [degree]    Phase [deg]

    1        1.000e+3     3.433e+1     1.000e+0        0.09°        0.00°

    2        2.000e+3     7.955e-5     2.317e-6     -163.36°     -163.45°

    3        3.000e+3     8.903e-5     2.593e-6      160.10°      160.01°

    4        4.000e+3     9.554e-5     2.783e-6     -161.54°     -161.63°

    5        5.000e+3     1.245e-5     3.625e-7      163.92°      163.83°

    6        6.000e+3     7.819e-5     2.277e-6      164.35°      164.26°

    7        7.000e+3     3.341e-5     9.732e-7     -137.91°     -138.00°

    8        8.000e+3     2.837e-5     8.262e-7      118.95°      118.86°

    9        9.000e+3     6.566e-5     1.912e-6      164.86°      164.77°

   10        1.000e+4     2.677e-5     7.798e-7     -111.55°     -111.64°

   11        1.100e+4     4.447e-5     1.295e-6       95.35°       95.26°

   12        1.200e+4     4.828e-5     1.406e-6     -167.08°     -167.17°

   13        1.300e+4     9.506e-6     2.769e-7     -113.02°     -113.11°

   14        1.400e+4     3.214e-5     9.361e-7      115.56°      115.47°

   15        1.500e+4     2.929e-5     8.530e-7     -146.44°     -146.53°

   16        1.600e+4     2.676e-5     7.793e-7      -29.93°      -30.02°

   17        1.700e+4     4.713e-5     1.373e-6      154.82°      154.73°

   18        1.800e+4     3.719e-5     1.083e-6     -117.86°     -117.95°

   19        1.900e+4     3.332e-5     9.705e-7       10.27°       10.18°

   20        2.000e+4     3.624e-5     1.056e-6     -173.58°     -173.67°

Total Harmonic Distortion: 0.000649%(0.000000%)





10 kHz, upto 5 harmonics

========================



Harmonic    Frequency     Fourier     Normalized     Phase      Normalized

 Number       [Hz]       Component     Component    [degree]    Phase [deg]

    1        1.000e+4     3.433e+1     1.000e+0       -0.32°        0.00°

    2        2.000e+4     4.600e-4     1.340e-5        6.05°        6.38°

    3        3.000e+4     4.738e-4     1.380e-5       83.50°       83.83°

    4        4.000e+4     5.676e-4     1.653e-5      -95.35°      -95.02°

    5        5.000e+4     5.736e-4     1.671e-5      116.27°      116.59°

Total Harmonic Distortion: 0.003037%(0.000000%)

The rails are generated from simulated filtered ac supply and have 1V injected signals to investigate PSRR.

The response curve is nice and flat in the audio band:

Attached Files

blameless_mosfet.asc (10.3 KB)

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Power Amplifier AB class

June 19, 2019, 11:48 am

≫ Next: Burst Decay, CSD, Mic Distance

≪ Previous: Blameless style lateral MOSFET amp

Amplifier board for amplifier repair and mod
Output power: 100W
THD+N: unknown
Slewrate: 18VuS
Bandwith: 15Hz..150kHz
Power supply: +/-10..50V
Amplifier topology: Voltage amplifier
Amplifier class: AB
Parts list: 2SA1943N, 2SC5200N, TTA004B, TTC004B, KSA992, KSC1845, BSS169, SSM3K15F, wima film capacitors, 1206 size chip resistors/ceramic capacitors, Piher trimmer, 0.22R low inductance KOA Speer resistors,

Attached Images

	amplifier kit2.jpg (618.3 KB)
	bottom PCB.jpg (220.6 KB)
	top PCB.jpg (179.4 KB)

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Burst Decay, CSD, Mic Distance

June 19, 2019, 11:58 am

≫ Next: pioneer a204R

≪ Previous: Power Amplifier AB class

I've put together a measuring setup to measure drivers. We're using Arta, our home made 'measuring device', a 80 x 80 x 80 cm box and Mikrotech Gefell mics. Now that everything seems to work as it should, some questions arise regarding various measurements and procedures.

1. Cumulative Spectral Decay vs. Burst Decay
What's the difference between Cumulative Spectral Decay (CSD) and Burst Decay (BD)? They both look like a waterfall plot (which is what I'm after) only the BD looks much cleaner and is much easier to produce. When using CSD you have to specify Window Rise Time whereas BD seems to determine this by itself. I'm just not sure what the difference is between these measurements?

2. Mic Distance
What would be a sensible mic distance for a waterfall plot? The measurements above was made from a 6,5 driver, nearfield with the mic just a few mm from the dustcap.

As a result, the measurement is pretty 'clean', meaning that it clearly shows the driver resonance at 10k without a lot of 'noise'. Off course the downside is that the frequency response is way off due to the minimal mic distance and I'm guessing that I am missing out on some speaker nonlinearities as well.

So what makes sense in terms of mic distance vs. cone diameter for this type of measurement?

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pioneer a204R

June 19, 2019, 12:37 pm

≫ Next: Powering Allo Boss

≪ Previous: Burst Decay, CSD, Mic Distance

Hi everyone,

I'm looking at a pioneer A204A which had badly distorted sound, I probed the input channel from the CD input to the input of IC9163N (analog switch) and inputs on both channels sound ok, but the output on pin 6 was distorted and the other channel sounded slightly better, I checked the chip and power supply( + and -) in is good, ground is also connected. I also checked the other inputs (tuner in) and they are the same. I temporarily bypassed the IC switch with a piece of wire on both channels and now its working on cd, so initially I though it must be a faulty switch, not ordered or replaced yet ( re-flowed the pins and they look good) But here is the question, is the input marked ST the clock that switches or cycles through the inputs? I do not see any voltage changes on this input when I select tuner and then cd. Or on any of the others for that matter, I presume I should see maybe a voltage spike? when the inputs are selected.

Thanks in advance.

Attached Images

pioneer a204r.jpeg (193.4 KB)

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Powering Allo Boss

June 19, 2019, 12:40 pm

≫ Next: Anyone has specs for Bose subwoofer from W163ML ?

≪ Previous: pioneer a204R

Hi everyone,
Just got Allo Boss DAC. Please help me in deciding how to power the Allo Boss or Pi. Or power both individually. I have below mentioned power adapters.

1. OnePlus 3 Dash Charger rated at 5V 4A with Type C cable.

2. OnePlus 2 Charger rated at 5V 2A with Micro USB cable.

3. I have other quality chargers, say of Amazon Echo 1st Gen rated at 5V 2A with Micro USB cable.

I see people suggesting to power Allo using a power bank, that is because of Linear Power supply. So I am new to this field, so please clarify.

If this is the case I have

4. Xiaomi Power Bank 10400mah rated at 5.1V 2.1A.

So what will be the best setup for me?
Let me know if I really need to buy any new power supply if it makes a lot of difference in sound quality.

Thanks,
Simar

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Anyone has specs for Bose subwoofer from W163ML ?

June 19, 2019, 12:48 pm

≫ Next: How to connect a Denon AU-320 step-up MC transformer

≪ Previous: Powering Allo Boss

Hello. A friend of mine works at car salvage factory, so he gave me 4 pieces of subwoofers by Bose, removed from various Mercedes W163ML. It looks like this: Mercedes Bose Sound System for the W163 ML - What's Inside The all work excellently and have very nice sound, but due to dual ported enclosure, they are tuned to very low frequency, with sharp fall-off, so with average 3'-4' bookshelf speakers, higher bass is missing, you only get lowest frequencies. So I'm thinking about building new enclosure for the speakers from these subwoofers, to make more wide ranged subwoofer. Maybe anyone already measured their specs, or have datasheet for them?

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How to connect a Denon AU-320 step-up MC transformer

June 19, 2019, 2:49 pm

≫ Next: Looking for a DIY dual mono DAC

≪ Previous: Anyone has specs for Bose subwoofer from W163ML ?

Hello,

I have a preamp that has four banks of micro switches for gain and input impedance. They are adjusted for my Denon DL 103R.

I have decided to add another deck that also has a 103R but comes with a Denon AU-320 step-up transformer.

My question is, should I reset the micro switches to 0 when inserting the transformer or will it automatically defeat the present set-up?

Is there another way to connect the transformer to avoid the cumbersome task of setting the switches back and forth when I switch from turntable A to turntable B?

Many thanks,

Horacio

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Looking for a DIY dual mono DAC

June 19, 2019, 5:30 pm

≫ Next: Toshiba 2SJ74V / 2SK170V - 4 matched pairs

≪ Previous: How to connect a Denon AU-320 step-up MC transformer

Unfortunately my SMSL M9 has given up the ghost because of a faulty ground on the unbalanced headphone output that pretty much hasn't been used until recently.

I have a few things here and there accumulated and I'd like to build a dual mono with AKM 4493/4495/4497. I've got one of the nice battery power supplies and a Fifo Pi from Ian's gb, some ultra BIB that would be a great for L and R separate +/- analog stages. All that I'm looking for now is a dual mono or two boards DIY style with dac. I can probably write arduino code in the future so something with expansion headers for software control would be cool.

I know of the diyinhk boards and the ebay/aliexpress stuff. Any recommendations for the DAC boards that may use better parts/design and offer better performance?

Regards
Colin

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Toshiba 2SJ74V / 2SK170V - 4 matched pairs

June 19, 2019, 6:14 pm

≫ Next: AliExpress do not allow searching their site without logging in (June 2019)

≪ Previous: Looking for a DIY dual mono DAC

I have 4 matched pairs of NOS Toshiba 2SJ74V / 2SK170V

I purchased them from a member here that goes by alweit on ebay.

Never used.

$60 shipped CONUS + Paypal
I will ship international, it just may cost a few dollars more.

Thanks

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AliExpress do not allow searching their site without logging in (June 2019)

June 19, 2019, 8:26 pm

≫ Next: Can you hear the uncompressed sample? test!

≪ Previous: Toshiba 2SJ74V / 2SK170V - 4 matched pairs

Found out today I couldn't do any search on AliExpress without being forced to a log-in page, after a quick search found the following thread below confirming the situation many others have experienced as of lately the same thing, well that was somewhat annoying, am wondering if it has anything to do with the trade war or else. :confused::(

AliExpress now requires login just to view item pages - http://budgetlightforum.com/node/67636

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Can you hear the uncompressed sample? test!

June 19, 2019, 8:30 pm

≫ Next: WTB: Pearl 2 PCB

≪ Previous: AliExpress do not allow searching their site without logging in (June 2019)

How Well Can You Hear Audio Quality? : The Record : NPR

My results with headphones in the computer: I could not hear a single difference with the Suzanne first track, so I switched on the independent dac and did the test seriously.

I clicked 4/6 of the uncompressed samples clicked the 128kbp for Jzze and Suzanne, this is not my type of music so I was relieved ,

btw, with a good headphone setup I found the differences were not obvious at all, I was stressed when I clicked the button lol, especially after choosing 128kbp with Suzzane, I was like, wow, this is not going well...

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