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Starkrimson® Ultra Amplifier Modules -- 250/500W into 8/4ohm

orchardaudio

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#1
I am proud to introduce these audio power amplifier mono modules that are capable of 250/500W into 8/4ohm loads.

IMG_1589_1200px.jpg IMG_1590_1200px.jpg IMG_1592_1200px.jpg

The modules can be preordered here: (preorder pricing ends May 31st):
https://orchardaudio.com/shop/ols/products/strk-ltr-mdl

Features:
  • Fully balanced from input to output (w/ differential input)
  • Differential and single-ended audio inputs
  • Extremely low noise and distortion
  • 2-ohm capable
  • Overcurrent, overvoltage, and thermal protection
  • 20A output current
Specifications:
  • Gain (balanced input): 19.05dB
  • Gain (single-ended input): 25.05dB
  • Signal-to-Noise Ratio (SNR): 120dB (A-weighted)
  • Power output into 8Ω/4Ω: 250W/500W
  • Input Impedance balanced/single-ended: 44k/22k
  • Sensitivity (balanced input): 5Vin for 250W into 8Ω
  • Sensitivity (single-ended input): 2.5Vin for 250W into 8Ω
  • Size: 4.95" (125.7mm) x 3.75" (95.3mm) x 1.45" (36.8mm)
    • 6 x M3 / 4-40 mounting holes
  • Required Power Supplies for Module (Hypex SMPS1200A100 provides all required voltages)
    • +/-36V (+/-30 to 42.5V) - Amplifier Power Rails
    • +15V (11 to 16V) - Mosfet Driver Supply - Referenced to -36V rail - 100mA minimum
    • +/-12V (+/-10 to 22V) - Analog Supplies - 100mA per supply minimum

Test Results for 8-ohm load for stereo configuration driven by single Hypex SMPS1200A100
Bench_Mode_10W_8ohm.JPG CCIF Ratio vs Measured Level_8ohm.JPG FFT Spectrum_Mutitone_8ohm.JPG Frequency_Response_8ohm.JPG SMPTE Ratio vs Measured Level_8ohm.JPG THD+N Ratio vs Frequency_10W_8ohm.JPG THD+N Ratio vs Measured Level_8ohm.jpg Wideband FFT Spectrum -40dB Output_8ohm.JPG


Test Results for 4-ohm load for stereo configuration driven by single Hypex SMPS1200A100
Bench_Mode_10W_4ohm.JPG CCIF Ratio vs Measured Level_4ohm.JPG FFT Spectrum_Mutitone_4ohm.JPG Frequency_Response_4ohm.JPG SMPTE Ratio vs Measured Level_4ohm.JPG THD+N Ratio vs Frequency_10W_4ohm.JPG THD+N Ratio vs Measured Level_4ohm.jpg Wideband FFT Spectrum -40dB Output_4ohm.JPG
 

Feyire

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#2
Looks great all round, congrats :cool:.

Any idea on the source for that small ~120Hz spur? Also, why not show 0dB output for wideband?
 

Veri

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#4
Looks good so far! Clean performance! Looking forward to hearing how the first production units hold up :)
 

DSS

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#6
This is great news. Wonder how much a kit costs to import to Portugal ... getting kind of expensive I guess but I would love the power headroom for my ATC SCM19 v2.
 

Matias

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#7
So the bill of materials of a DIY build would be:

2x Starkrimson Ultra modules: 150 usd (regular price)
Hypex SMPS1200A100: 260 usd
Modushop case: 370 usd
Cables, connectors, screws: ~100 usd?
Total: ~1,000 usd?
 
OP
orchardaudio

orchardaudio

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Thread Starter #8
So the bill of materials of a DIY build would be:

2x Starkrimson Ultra modules: 150 usd (regular price)
Hypex SMPS1200A100: 260 usd
Modushop case: 370 usd
Cables, connectors, screws: ~100 usd?
Total: ~1,000 usd?
The cost of two (2) assembled modules at the regular price is $1050. (Currently, 850, until May 31st.)

The $150 option is for the unpopulated board and then you have to buy all the parts yourself and assemble them. The parts come out to around $450 for two (2) boards.

I also recommend adding the Hypex Soft-start module and cable kits to your list.
 

Matias

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OP
orchardaudio

orchardaudio

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Thread Starter #10

Matias

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#13
@amirm we would like to see it reviewed please.
 
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orchardaudio

orchardaudio

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Thread Starter #14
With preorder pricing a stereo build will cost you:
2 x Modules -- $850
1 x SMPS1200A w/ SS module and wiring kit -- $350
1 x Enclosure - $370
Miscaleions nuts bolts, etc - $100
Total: $1670 USD

The joy of building this with your blood, sweat, and tears - priceless (oh that's good for a MasterCard commercial...)

@Matias @DSS
 
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orchardaudio

orchardaudio

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Thread Starter #15

DSS

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#16
With preorder pricing a stereo build will cost you:
2 x Modules -- $850
1 x SMPS1200A w/ SS module and wiring kit -- $350
1 x Enclosure - $370
Miscaleions nuts bolts, etc - $100
Total: $1670 USD

The joy of building this with your blood, sweat, and tears - priceless (oh that's good for a MasterCard commercial...)

@Matias @DSS
I know! I am just worried about the import duties. Once I bought some caps and customs charged almost 30%, so I estimate that for me this kit would come close to 1800€ (this is without shipping cost ...)
 
Last edited:
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orchardaudio

orchardaudio

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Thread Starter #17
I know! I am just worried about the import duties. Once I bought some caps and customs charged almost 30%, so I estimate that for me this kit would come close to 1800€ (this is without shipping cost ...)
I understand if you are in the EU there will not be any customs fees on the enclosures as those ship from Italy. This is also the reason I am having folks buy enclosure directly from Modushop.
 
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orchardaudio

orchardaudio

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Directly from AP website:

SMPTE

SMPTE IMD is a technique for measuring IMD standardized by the Society of Motion Picture and Television Engineers (SMPTE). The standard was updated in 2005 and reaffirmed in 2010, and is now managed by the Institute of Electrical and Electronics Engineers (IEEE) as IEEE RP 120-2005.

The stimulus is a strong low-frequency interfering signal (f1) combined with a (typically) weaker high frequency signal of interest (f2).
For SMPTE, f1 is usually 60 Hz and f2 is usually 7 kHz, at a ratio of f1:f2=4:1. f1 must be ≤ (f2 / 6). The stimulus signal is the sum of the two sine waves. In a distorting DUT, this stimulus results in an AM (amplitude modulated) waveform, with f2 as the "carrier" and f1 as the modulation.

In analysis, f1 is removed, and the residual is bandpass filtered and then demodulated to reveal the AM modulation products. The rms level of the modulation products is measured and expressed as a ratio to the rms level of f2. The SMPTE IMD measurement includes noise within the passband, and is insensitive to FM (frequency modulation) distortion.

The APx500 implementation of SMPTE IMD provides the capability to vary the stimulus frequencies, and to choose alternative stimulus ratios of 1:1 and 10:1.

CCIF (IMD ITU-R)

The CCIF IMD method is described in document no. 11 of the Commission Mixte, CCIF/UIR, March 1937, issued by the International Telephonic Consultative Committee (CCIF). CCIF no longer exists as an organization, having become the ITU-R division of the International Telecommunications Union (ITU). This method is also referred to as IMD (ITU-R).

The CCIF stimulus is two equal-level high-frequency tones f1 and f2, centered around a frequency called the mean frequency, (f1+f2)/2. The tones are separated by a frequency offset called the difference frequency. The two tones intermodulate in a distorting DUT to produce sum and difference frequencies.

For analysis CCIF selectively measures the 2nd and 3rd order intermodulation products, combines their values arithmetically and provides a result that is the ratio of the sum of the products to a reference voltage defined as 2x the voltage of f2 (effectively, the sum of f1 and f2). In the APx500 implementation, the 4th and 5th order products are also measured and reported in the distortion product view.

Because the stimulus tones are high in frequency, CCIF is a useful measurement for observing distortion in devices that exhibit distortion that rises with frequency. Since the tones by default are only 80 Hz apart, much of the energy contained in the distortion products will fall near or below the stimulus tones. This makes CCIF a good choice for measuring distortion at higher frequencies in band limited devices, where harmonic distortion products from high-frequency stimulus tones would fall out of band.

CCIF measurements are made in the same way as DFD measurements, differing only in amplitude calibration. CCIF results are expressed as values 6.02 dB higher than DFD results.
 

Vini darko

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#20
Directly from AP website:

SMPTE

SMPTE IMD is a technique for measuring IMD standardized by the Society of Motion Picture and Television Engineers (SMPTE). The standard was updated in 2005 and reaffirmed in 2010, and is now managed by the Institute of Electrical and Electronics Engineers (IEEE) as IEEE RP 120-2005.

The stimulus is a strong low-frequency interfering signal (f1) combined with a (typically) weaker high frequency signal of interest (f2).
For SMPTE, f1 is usually 60 Hz and f2 is usually 7 kHz, at a ratio of f1:f2=4:1. f1 must be ≤ (f2 / 6). The stimulus signal is the sum of the two sine waves. In a distorting DUT, this stimulus results in an AM (amplitude modulated) waveform, with f2 as the "carrier" and f1 as the modulation.

In analysis, f1 is removed, and the residual is bandpass filtered and then demodulated to reveal the AM modulation products. The rms level of the modulation products is measured and expressed as a ratio to the rms level of f2. The SMPTE IMD measurement includes noise within the passband, and is insensitive to FM (frequency modulation) distortion.

The APx500 implementation of SMPTE IMD provides the capability to vary the stimulus frequencies, and to choose alternative stimulus ratios of 1:1 and 10:1.

CCIF (IMD ITU-R)

The CCIF IMD method is described in document no. 11 of the Commission Mixte, CCIF/UIR, March 1937, issued by the International Telephonic Consultative Committee (CCIF). CCIF no longer exists as an organization, having become the ITU-R division of the International Telecommunications Union (ITU). This method is also referred to as IMD (ITU-R).

The CCIF stimulus is two equal-level high-frequency tones f1 and f2, centered around a frequency called the mean frequency, (f1+f2)/2. The tones are separated by a frequency offset called the difference frequency. The two tones intermodulate in a distorting DUT to produce sum and difference frequencies.

For analysis CCIF selectively measures the 2nd and 3rd order intermodulation products, combines their values arithmetically and provides a result that is the ratio of the sum of the products to a reference voltage defined as 2x the voltage of f2 (effectively, the sum of f1 and f2). In the APx500 implementation, the 4th and 5th order products are also measured and reported in the distortion product view.

Because the stimulus tones are high in frequency, CCIF is a useful measurement for observing distortion in devices that exhibit distortion that rises with frequency. Since the tones by default are only 80 Hz apart, much of the energy contained in the distortion products will fall near or below the stimulus tones. This makes CCIF a good choice for measuring distortion at higher frequencies in band limited devices, where harmonic distortion products from high-frequency stimulus tones would fall out of band.

CCIF measurements are made in the same way as DFD measurements, differing only in amplitude calibration. CCIF results are expressed as values 6.02 dB higher than DFD results.
Thanks for the quick reply.
 
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