BOSC - HiFi Monoblock Class-D Amp

[orchardaudio]

Currently Under Development

Preliminary Specifications:

Gain: 16.8dB or 6.92
Signal to Noise Ratio (SNR): ~120dB
Total Harmonic Distortion (THD): <0.0003% (-110dB) @ 7W
Frequency Response: DC - 40kHz
Sensitivity: 2.5Vin for 37.5W into 8Ω
Input Impedance: 5kΩ fully balanced
Output Power: 100W into 8Ω w/ 48V Power Supply
Output Power: 150W into 8Ω w/ 56V Power Supply
Size: 5.5" (14cm) x 4.8" (12.2cm) x 1.9" (4.8cm)

https://img1.wsimg.com/isteam/ip/80cc3d69-5af5-47d4-a047-53c1246a6080/BOSC_White_1200_630(40x21).jpg/:/cr=t:6.06%25,l:9.03%25,w:89.29%25,h:89.29%25/rs=w:600,cg:true,m

To receive updates and get access to special early bird pricing sign up here:
https://www.indiegogo.com/projects/bosc-hifi-monoblock-class-d-amp/coming_soon

[Firebottle]

What's the power supply, standard SMPS or resonant, or other?

[orchardaudio]

What's the power supply, standard SMPS or resonant, or other?

Standard SMPS - All of the performance specs are with the SMPS supply.

[orchardaudio]

To receive updates and get access to special early bird pricing sign up here:
https://www.indiegogo.com/projects/bosc-hifi-monoblock-class-d-amp/coming_soon

[Bigman80]

To receive updates and get access to special early bird pricing sign up here:
https://www.indiegogo.com/projects/bosc-hifi-monoblock-class-d-amp/coming_soonLink isn't working for me Leo.

[orchardaudio]

Link isn't working for me Leo.

I just tried and its working.

[Bigman80]

I just tried and its wirking.Herehttps://uploads.tapatalk-cdn.com/20190630/21b0a362f38bb4690b647b71e0067f37.jpg

[Edward]

Oli, looks like your browser is incorrectly taking you to sharesale rather than indiegogo. Works fine for me here with no redirects.

[Bigman80]

Oli, looks like your browser is incorrectly taking you to sharesale rather than indiegogo. Works fine for me here with no redirects.I'll try on the laptop.

[orchardaudio]

If you are really interested in this product and would like to be one of the first people to get it at a reduced price, reserve now for $1. Only 55 spots available:
https://orchardaudio.com/shop?olsPage=products%2Fbsc-mplfr

[Edward]

If you are really interested in this product and would like to be one of the first people to get it at a reduced price, reserve now for $1. Only 55 spots available:
https://orchardaudio.com/shop?olsPage=products%2Fbsc-mplfr

Does a reservation imply an obligation to purchase? If so what is the purchase price please?

Is $1 for a pair of monoblocks or just for one amp?

[orchardaudio]

Does a reservation imply an obligation to purchase? If so what is the purchase price please?

Is $1 for a pair of monoblocks or just for one amp?

$1 is for a two amplifiers. If you only need 1 we can work something out.

There is no obligation to purchase with the reservation.

Full pricing and updated specs here:
https://orchardaudio.com/bosc

[montesquieu]

Ok so long as there’s no obligation I paid my $1. Curious about these as a bit of a class d fan but will need more info before proceding.

[orchardaudio]

Ok so long as there’s no obligation I paid my $1. Curious about these as a bit of a class d fan but will need more info before proceding.

What info are you looking for?

[montesquieu]

Lots of questions. Are these just class d only? Any input stage? Damping factor? What’s the current delivery like? Pics/specs of the power supply? More to the point how do they sound with various types of speakers? (Subjective obviously but even informal reviews on forum can provide valuable info).

If you look at the info provided on design approach and topology for the NuPime ST10 and STA9 amps - both excellent class d amps, but also a good example of how to sell class d. They have class a input stages btw.

[orchardaudio]

Lots of questions. Are these just class d only? Any input stage? Damping factor? What’s the current delivery like? Pics/specs of the power supply? More to the point how do they sound with various types of speakers? (Subjective obviously but even informal reviews on forum can provide valuable info).

If you look at the info provided on design approach and topology for the NuPime ST10 and STA9 amps - both excellent class d amps, but also a good example of how to sell class d. They have class a input stages btw.

It is a full class-d amplifier using gallium nitride (GaN) output devices in a full-bridge configuration (fully balanced output). The modulator is fully custom and proprietary. It is not based on any modules like nCore or ICE.

I just measured the damping factor at 1kHz to be 425, so for the specs I will say >400. More importantly BOSC allows you to suspend the amp from the back of the speaker eliminating long cables which can hurt a great damping factor (see picture below).

The input stage is a Texas Instruments OPA1612 which in my opinion is the best audio monolithic op amp currently available.

The Power supply is a 56V 250W swithing power supply - All tests and specs are performed and measured with this power supply. (see picture below)

I am not able to comment on how they sound, but I can say that they will have no issues with driving any kind of speakers. A review will be out shortly. Also a member of this forum has agreed to try them and post findings. That will be a few weeks.


https://c1.iggcdn.com/indiegogo-media-prod-cld/image/upload/c_limit,w_600/v1562263707/p1y7r643q36ebglp1fen.jpg

[montesquieu]

It is a full class-d amplifier using gallium nitride (GaN) output devices in a full-bridge configuration (fully balanced output). The modulator is fully custom and proprietary. It is not based on any modules like nCore or ICE.

I just measured the damping factor at 1kHz to be 425, so for the specs I will say >400. More importantly BOSC allows you to suspend the amp from the back of the speaker eliminating long cables which can hurt a great damping factor (see picture below).

The input stage is a Texas Instruments OPA1612 which in my opinion is the best audio monolithic op amp currently available.

The Power supply is a 56V 250W swithing power supply - All tests and specs are performed and measured with this power supply. (see picture below)

I am not able to comment on how they sound, but I can say that they will have no issues with driving any kind of speakers. A review will be out shortly. Also a member of this forum has agreed to try them and post findings. That will be a few weeks.


https://c1.iggcdn.com/indiegogo-media-prod-cld/image/upload/c_limit,w_600/v1562263707/p1y7r643q36ebglp1fen.jpg

Thanks that's all very useful info, thanks. I see the pic shows balanced input which could be handy in many cases.

It seems to be quite the thing at the moment for Class D manufacturers to add a discrete input stage, sometimes single ended, sometimes tweaked in some way (in some cases I believe even by digital singnal processing) to give a small amount of first and second harmonic associated with tubes, with the stated intent of giving a warmer/more triodey feel to whatever Class D main board is in use. It's interesting that you have opted to stick with an op amp - no doubt for the distortion specs and so on you mention.

[orchardaudio]

The AMP has a true balanced input, but also comes with an RCA to XLR adapter for those that would need it.

[Barry]

How well do these amplifiers perform when used with electrostatic speakers? I would consider using them with my Quad '57s.

Thanks

[orchardaudio]

How well do these amplifiers perform when used with electrostatic speakers? I would consider using them with my Quad '57s.

Thanks

I do not have this type of speaker. I don't see any issue with it. The performance will still be very good as long as the load presented to the amplifier is in the 4 to 8 ohm range.

Where are you located I can potentially send you sample units to try in 3 to 4 weeks.

[Barry]

I do not have this type of speaker. I don't see any issue with it. The performance will still be very good as long as the load presented to the amplifier is in the 4 to 8 ohm range.

Where are you located I can potentially send you sample units to try in 3 to 4 weeks.

That is very kind of you, but my speakers present a very difficult load to the amplifier (varying over an impedance range of 30 Ohm to 1.5 Ohm), so I don't think your amplifiers would suit.

Thanks anyway for the offer.

[Sherwood]

That is very kind of you, but my speakers present a very difficult load to the amplifier (varying over an impedance range of 30 Ohm to 1.5 Ohm), so I don't think your amplifiers would suit.

Thanks anyway for the offer.

I have Magneplanar 1.7 speakers which present a much more difficult load than the QUADS. I can strongly recommend the NuPrime STA-9 power amp. I use a pair of these in mono mode which output just under 300w. They provide a vice like grip on the Maggies with a very smooth tube-like sound. NuPrime have recently introduced a slightly lower powered model (the STA-6), which I am sure would be great with the QUADS.

[orchardaudio]

I have a friend with the Magnapan 1.7i speaker, BOSC had no issues with those.

[orchardaudio]

A pair of these is on their way to Oli for evaluation.

Also if you are interested I posted the latest performance measurements here:
https://www.audiosciencereview.com/forum/index.php?threads/bosc-hifi-monoblock-class-d-amp.7750/page-2#post-210892

[Bigman80]

A pair of these is on their way to Oli for evaluation.

Also if you are interested I posted the latest performance measurements here:
https://www.audiosciencereview.com/forum/index.php?threads/bosc-hifi-monoblock-class-d-amp.7750/page-2#post-210892Yes they are!

I'm looking to give these a thorough test as it'll be a first in depth Class D experience for me other than a ICE derived power amp I tried for 10 minutes, which wasn't as impressive as I'd have liked.

[Firebottle]

That is very kind of you, but my speakers present a very difficult load to the amplifier (varying over an impedance range of 30 Ohm to 1.5 Ohm), so I don't think your amplifiers would suit.

Thanks anyway for the offer.

I have driven my '57's with 3 different class D amps without any problem Barry.

[orchardaudio]

An awesome review for the BOSC amp:

"Class-D amplifiers generally trigger reactions and opinions of a generic, mass-market sound. And I’ll admit, I tend to not be too curious about anything based around that amplification method. But Leonid (Leo) Ayzenshtat’s Class-D amplifiers continually force me to think differently. They prove that it isn’t about the type of thing, but rather about how skillfully a thing is made."

"I wanted to stop my heart so I could hear the music better. I was being sucked in, pushed out, and unable to focus on anything else but the music. There were all the little bird-like chimes, dancing between clicks and pings and bongs of xylophone harmonics with dry reed raspy sounds zooming in and out, floating on top of deep rolling strings and organ-like bass. I didn’t want to miss a moment of it."

Read the full review here:
https://theaudiobeatnik.com/reviewin...sc-monoblocks/

[orchardaudio]

https://theartofsound.net/forum/showthread.php?62737-Bigblog-The-Revolving-Door-of-HiFi-Auditioning&p=1114154#post1114154

[orchardaudio]

Kickstarter launching next week. Check out the project video:
https://youtu.be/qo4ssUfE4rg.

Sign up for our mailing list to learn when Kickstarter project goes live:
www.orchardaudio.com/bosc

[orchardaudio]

Kickstarter is live! Grab the early bird special while supplies last:
https://www.kickstarter.com/projects/orchardaudio/bosctm-hifi-monoblock-audio-amplifier?ref=1hvtb6

[Lawrence001]

Where's the price on the website? Maybe I'm going blind.

Sent from my POT-LX1 using Tapatalk

[Ali Tait]

Looks like $1499, with 26% off for early bird contributors.

[orchardaudio]

Where's the price on the website? Maybe I'm going blind.

Sent from my POT-LX1 using Tapatalk

Right now with the early bird special it is 1099 for a pair. Shipping is not included and will be charged separately at a later date.

[orchardaudio]

Looking for individuals with reddit accounts. If you have one please post about this project on there.

[antonio]

Picked up the amps from AliT at the show yesterday and have them plugged in and playing in the main system. Took approx. 20 minutes for them to get going, but straight off very impressed with the sq. They are replacing Accustic Arts mono blocks, so not a very fair comparison. The Orchards give little away in the detail and tonality stakes, but there is obviously greater slam and presence with the Arts monos. In no rush to change back yet, but will have to since a fairer comparison with have to be made with my A60 in the coming days.

[orchardaudio]

Picked up the amps from AliT at the show yesterday and have them plugged in and playing in the main system. Took approx. 20 minutes for them to get going, but straight off very impressed with the sq. They are replacing Accustic Arts mono blocks, so not a very fair comparison. The Orchards give little away in the detail and tonality stakes, but there is obviously greater slam and presence with the Arts monos. In no rush to change back yet, but will have to since a fairer comparison with have to be made with my A60 in the coming days.

Thank you for participating in the tour. Looking forward to your full evaluation.

[orchardaudio]

Less than 2 weeks left!

https://www.kicktraq.com/projects/orchardaudio/bosctm-hifi-monoblock-audio-amplifier/minichart.png (https://www.kickstarter.com/projects/orchardaudio/bosctm-hifi-monoblock-audio-amplifier?ref=1hvtb6)

[orchardaudio]

Full test results posted here:
https://www.audiosciencereview.com/forum/index.php?threads/bosc-hifi-monoblock-class-d-amp.7750/post-210892

[orchardaudio]

BOSC quality...

Every BOSC amp is hand-assembled and tested in the USA, by yours truly.

The circuit board (PCB) uses a high-quality dielectric, has a gold finish (ENIG), and is assembled in Eatontown, NJ.

The components all come from high-end semiconductor manufacturers: Texas Instruments; Analog Devices; Murata; Panasonic; and NXP; to name a few.

The output filter inductors use oxygen-free copper (OFC) and are specifically made for Class-D amplifiers.

Even though Orchard Audio is new to the market, I have multiple patents and over a decade of experience in designing audio electronics.

I believe that you will be very happy with both the sound and quality of BOSC amplifiers.

Contact me with any questions!

https://www.kickstarter.com/projects/orchardaudio/bosctm-hifi-monoblock-audio-amplifier?ref=1hvtb6

[orchardaudio]

The BOSC amps made The Audio Beatnik's best of 2019 list:
https://bit.ly/2tt38Nd

[orchardaudio]

I will be doing a demo in Stamford, CT on February 1st. Let me know if you would be interested in coming. There are only 5 spots left.

[orchardaudio]

Customers asked for it, here it is...BOSC amplifier with all connectors on the back.
Let me know what you think:
https://orchardaudio.com/bosc

https://www.audiosciencereview.com/forum/index.php?attachments/img_1444-jpg.53363/

https://www.audiosciencereview.com/forum/index.php?attachments/img_1447-jpg.53364/

[orchardaudio]

Ron Nagle - Enjoy the Music

"The Orchard amplifiers at $1499.99 set a new benchmark for value, laser-like clarity, and inner detail at this price range. Highly recommended."

and

"Power on and my very first impression was clean and clear music overlapping what was a very dead black background."

http://www.enjoythemusic.com/magazine/equipment/0820/Orchard_Audio_BOSC_Starkrimson_ClassD_Monoblock_Am plifier_Review.htm

[orchardaudio]

Save 15% during our holiday sale, through December 10th.

www.orchardaudio.com/shop

Use code "holiday15%" at checkout.