Best solution for 13 channel amplification

[Hawkmoon4576]

Happy new year all! Go easy on an absolute rookie here thank you.

I currently have a 7.2.4 home theatre audio setup with a Denon AVR-X6700H receiver. My goal is to use all available channels which requires amplification of the two remaining channels to create a 7.2.6 setup.

Little did I know this would open me to the wide world of monoblocks, xlr vs rca power bricks, etc... but I am enjoying the ride thanks to communities such as this one.

I would love thoughts and commentary on this solution thankyou.

I've decided to amplify my Front Main Speakers which are Adelaide Speakers Summoner 863SQTL (https://www.adelaidespeakers.com/summoner-floorstanders.html) as all other speakers can be driven by the AVR.

2 x Fosi Audio v3 Mono each with 48V 10A power adapters and Fosi DC Power Filters
1 x ART Pro Audio CLEANBox Pro Dual Channel Level Converter (https://derringers.com.au/art-pro-audio-cleanbox-pro-dual-channel-level-converter)
2 x XLR-XLR Cables

Is there a better bang for buck solution than the Fosi v3 monos?

Will the unbalanced to balanced (RCA to XLR) conversion resolve low volumes reported by some others with a similar setup using RCA-RCA?

Is it better to position the amplifiers closer to the speakers for short speaker wire runs OR closer to AVR for short XLR runs?

Is some sort of power filtering power board with the investment for my whole setup?

Considering some reports of high heat with the Fosi's and the warmer climate where I live should I invest in silent fans for better airflow?

Cheers!

 

[Blumlein 88]

Welcome to ASR.

Using RCA to XLR conversion just using cables to convert will lower the levels further. Whether you use short XLR or long XLR most likely makes no difference you'll hear. I would go with whichever is most convenient for setting this up in your room. I probably would go with shorter RCA to RCA (this amp has RCA inputs). The amp has two gain settings on RCA. I don't know much about reports of low gain, but it has 31 db at high gain over RCA. That is probably more than average for amps. This doesn't mean you couldn't go with long RCA interconnects, but there is a slightly higher chance of picking up hum or higher noise. Using any decent RCA based upon RG6 coax is likely to be fine.

Power filtering gear is not going to help anything.

I don't know of a better bang for buck choice if the amp has the power you need. Not sure how much heat is a problem with these.

I assume you have seen this review here on ASR by Amir, but if not take a look.

Fosi Audio V3 Mono Amplifier Review

This is a review and detailed measurements of the Fosi Audio V3 Mono class D amplifier. It was sent to me by the company. The price with the power supply I tested is US $139.99. I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime...

www.audiosciencereview.com

 

[Hawkmoon4576]

Thank you for your response and thoughts. To combat the lower RCA output I am considering the ART CLEANBoxPro which converts unbalanced inputs to balanced outputs with a maximum gain of 21dB.

The ASR review is excellent and has helped me commit to the Fosi v3 monos as my solution.

Cheers!

 

[Hawkmoon4576]

I thought I'd provide an update here for anyone investing in the Fosi V3 monos and/or amplifying remaining channels on an AVR.

I ended up purchasing:
- 2 x Fosi V3 Monos each with 48V 5A power bricks
- 1 x ART Pro Audio CLEANBox Pro Dual Channel Level Converter (https://artproaudio.com/diboxes/product/317572/cleanboxpro)
- 2 x XLR-XLR M-F 3m (10ft) Cables
- 1 x Dual RCA to Dual RCA M-M 1m (3ft) Cable
- 2 x Speaker Wiring 1m (3ft)
- 1 x Meross Smart Power Plug
- 1 x 4-Port GPO Power Board 10A

I hooked everything up to my power and AVR using the Front preouts and set the Fosi V3 Monos to Auto Power and XLR. I configured my Denon AVR-X6700 for 13.1 channels and set the preamp to the front speakers.

I've currently set the output level on the ART Pro to 50% (12 o'clock) which is working nicely but I intend to run the Audyssey setup again to balance my whole system and tweak this as required. My front speakers are Adelaide Speakers Summoner 863SQTL plus upgraded bass driver with power rating 140 wrms, nominal impedance 8 ohms, frequency repsonse 28Hz-30kHz +/-2dB and sensitivity 91 dB 1w/1m. The Fosi v3 Mono blocks are driving these with ease and solid power. I used the ART device to avoid what some others have reported when using the RCA inputs that being low power.

Also as others have reported, after watching a 2-hour movie the Fosi's were quite warm on the touch. Even after leaving them on standby overnight they were warm to the touch. In the hope of extending their life, I've setup a Meross Smart plug and 4-port power board with the ART CLEANBox and both Fosi's connected. Using Google Home I've configured Household Routines Automations to power this board on and off when my projector is turned on and off so no more standby power. Hopefully this will avoid the need for active cooling on the mono blocks.

All in all I am very happy with my upgrade. I will report back with how this goes throughout the life of the gear too in the hope it helps someone out there.

Cheers!