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BOSC - HiFi Monoblock Class-D Amp

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#81
Anyway, the BOSC name will be changing to Starkrimson (another pear variety). This is because of a trademark issue with Bosch Gmbh.
I believe the amp case uses a top plate? If so, it may be beneficial from a customer support perspective to notify the owner's of amps already shipped and offer a new top plate with "Starkrimson" at cost (inc shipping, P&P, taxes). The reasoning behind this is that people receiving a version with BOSC on it, may feel they will end up with an amplifier that is no longer mentioned online a few months from now and therefore loses resale value if they want to sell it in the future.

Maybe an easier way is have the "Starkrimson" product page always mention that early but identical production units were called BOSC and this was changed due to a trademark dispute with Bosch Gmbh, but there is no technical difference whatsoever.

Or do both.
 
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orchardaudio

orchardaudio

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Thread Starter #82
I believe the amp case uses a top plate? If so, it may be beneficial from a customer support perspective to notify the owner's of amps already shipped and offer a new top plate with "Starkrimson" at cost (inc shipping, P&P, taxes). The reasoning behind this is that people receiving a version with BOSC on it, may feel they will end up with an amplifier that is no longer mentioned online a few months from now and therefore loses resale value if they want to sell it in the future.

Maybe an easier way is have the "Starkrimson" product page always mention that early but identical production units were called BOSC and this was changed due to a trademark dispute with Bosch Gmbh, but there is no technical difference whatsoever.

Or do both.
Thank you I will take this into consideration, it all depends on what I am allowed to do per the final agreement with Bosch.
 

restorer-john

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#85
Thank you I will take this into consideration, it all depends on what I am allowed to do per the final agreement with Bosch.
The world is indeed a strange place when a company like Bosch makes it difficult for you to name a product after a botantist who cultivated and had pears named after him over 200 years ago. The name predated Robert Bosch himself by six decades.

I would have told them exactly where to go.
 
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orchardaudio

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Thread Starter #86

Matias

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#87
@orchardaudio could you please post THD+N versus power for 1kHz in 4 ohms, and also the power where it reaches 1% with 1kHz into 4 ohms?
Thanks.
 
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orchardaudio

orchardaudio

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Thread Starter #88
@orchardaudio could you please post THD+N versus power for 1kHz in 4 ohms, and also the power where it reaches 1% with 1kHz into 4 ohms?
Thanks.
It will never get to 1% distortion with the provided power supply. This is because the power supply will shut down due to overcurrent before that happens.

I will post the other info later.
 
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orchardaudio

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Thread Starter #90
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orchardaudio

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Thread Starter #91
"At 1 W into an 8 Ω load, the BOSC’s distortion is below the Audio Precision analyzer’s measurement capabilities."
I did a loopback test on my APX525. Clearly, at some voltages, it has better performance than at others. You can clearly see the spikes in distortion when the automatic gain control kicks in.

As an example when an amplifier is outputting 11Vrms (~15W in 8ohm or ~30W into 4 ohm), the THD+N the analyzer can measure will not be any better -105dB (0.00056%).

THD+N Ratio_Loop_Back.jpg
 

SIY

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#92
I did a loopback test on my APX525. Clearly, at some voltages, it has better performance than at others. You can clearly see the spikes in distortion when the automatic gain control kicks in.

As an example when an amplifier is outputting 11Vrms (~15W in 8ohm or ~30W into 4 ohm), the THD+N the analyzer can measure will not be any better -105dB (0.00056%).
My current workaround, which I’ll use on the next thing you send me, is a super low distortion external oscillator (Vicnic) and a twin T filter. That gets me down to the ppm level.
 
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orchardaudio

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