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Amber Series 70

Stereo Power Amplifier (1978-85)

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Amber Series 70


Power output: 70 watts per channel into 8Ω (stereo), 200W into 8Ω (mono)

Frequency response: 20Hz to 20kHz

Speaker load impedance: 4Ω (minimum)

Year: 1978



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Reviewed Feb 07th, 2019 by theaudiohiffle

I currently have an early S-70 in my second system, driving Thiel 2.2 speakers, and fed by a Carver C-2 preamplifier. This combo punches way, way above its weight class, sounding very similar to my main system of Audio Research SP6 (refurbed) feeding Outlaw M200 monoblocks into Thiel 3.5 speakers.

This is my second Amber .... I bought one way back in the 80's after its glowing review in the Abso!ute Sound and used it in my system for several years. I then sold it (for a song) along with a Citation 11 to my best friends who are classical musicians. Those two pieces still work flawlessly and sound great in their system.

A S-70 in good working condition is one of the best bargains in hi-fi, in my opinion. I rate it only 3-1/2 starts simply because equipment this old does not use modern and more transparent passive devices in the signal path. Accordingly, while neutral musically it has a slightly old fashion high-end sound.

Reviewed Feb 16th, 2016 by ecb015

I worked at Amber in 1980 in exchange for parts to build my own amp. The LM391 were hand selected to not need offset adjustments. All amps were burnt in at half power both channels better than FTC specifications. Output transistors were still being matched in those days. The owners were UVa students, one EE and the other a business major. The name Amber is based on the color of the LED, which was new then.

Reviewed Jan 21st, 2015 by TBroosteRR

I've been messing around with Amber amplifiers since 1983. I have 3 series 70 amps that I have hooked up as monoblocks. I had them upgraded by a guy in town and they are just great. Good separation, base response, power output and highs are clear and beat seems to be right on with no delays. The distortion is very small and they are very quiet solid state amps. They have been reliable. Only regret is, that I bought these from people used and not new. Each amp has a switch that will make them monoblock or stereo. So, you actually only need one for your stereo. I've never used them on anything but audiophile speakers and pre-amps. They should be able to preform in any situation. They don't smell when heated up. They don't get to hot, because of the cooling fins on each side. They are heavy and I guess weigh about +/- 27 pounds each.



re: Series 70

Hi I have an Amber Series 50C on the bench undergoing repair. I'm rebuilding the entire left channel on one side on discovering a number of charred parts. Fortunately, all the tracks are in good nick, so I got the go ahead for repair.

Thing is, some of the resistors are unidentifiable, and a meter will not help here. In the absence of any schematic diagrams or service manuals, can anyone help me out?
Rhea Bonsey

re: Series 70

re: Series 70

Thanks for thew great info on the s-70. Could you possibly tell us what upgrades you had made to the amp?


Bob Cham

re: Series 70

High end amplifiers intentionally didn't have output protection relays. Keep the contacts clean on the PCB. When mine failed many years later it took out my speaker too. So fuse to the lower rating of the speaker and use with a passive subwoofer. At least use the high pass caps from the subwoofer crossovers to protect you book self speakers. Believe it or not, high end speakers like the old Infinity Kappa towers have DC blocking caps on all of their speakers including the woofer. The higher ones are called crossovers.

This website is not affiliated with or sponsored by Amber. To purchase Series 70 spares or accessories, please contact the company via their website or visit an authorised retailer.