Sansui AU7700 Integrated Amp- Vintage Audio Review Episode

In this episode I look at the performance, & features of a Sansui AU7700 Integrated amp.
00:00 Introduction
01:39 Outside “tour”
04:16 Inside view with covers removed
07:04 Measurements begin- THD SNR @ 5w
08:45 Freq Response
10:06 Output Impedance
10:39 Crosstalk
11:28 Max Power 8 & 4 ohms
14:14 THD vs Freq & output power (8ohms)
15:03 Multitone
15:25 System Noise
16:24 Filters
17:02 IMD
17:46 Input to Input Isolation
19:08 THD amp Only (8ohms)
19:58 Freq Response Power amp only (8ohms)
20:54 Phono Stage Measurements
22:41 Preamp only meaurements
26:50 Listening & Final Comments

[@ragnarhairybreeks]

Once again , another great vid. Thanks!

[@vintageaudioreview]

I appreciate you taking the time to let me know !

[@TriAmpHiFi]

Cool. Thanks. These Sansuis are great to see. 👍 Acid Jazz, Funk & Brass 🔈🔉🔊

[@vintageaudioreview]

Thanks for the comments as always!!

[@TriAmpHiFi]

@@vintageaudioreview . Oh BTW, I never really found a Bryston 2B LP-Pro. So I took a chance on a brand new AvanTone CLA-100. Inside components are decent. I haven't finished my chain yet so I don't know how it performs. (as my tweeter amp)

[@vintageaudioreview]

@@TriAmpHiFi Am not familiar with AvanTone gear. Am very happy with my Bryston amps, but if you can't find one, then you need soemthing so hopefully your purchase will do the trick.

[@kirkbac]

What a great review. My question is whether it’s worth purchasing this unit and pay a technician to restore it or buying new?

[@vintageaudioreview]

Thanks for the comment and question. I would much rather have a classic piece of vintage gear like this one. You actually have 3 aux inputs if you wanted to use the tuner input for a streamer. Like having a classic car instead of a Corolla or Civic. You would not necessarily have to have it restored if it worked fine.

[@Douglas_Blake_579]

Had one of those for about a year. Loved it, great sound. But looking at the low power tests on your QA, I think you might want to check the bias on that left channel output.

[@vintageaudioreview]

Thanks for the suggestion, Douglas. If I did n't mention that I checked or adjusted the bias and offest voltage in the video, then I probably did not (I have not watched it since I uploaded about a month ago, so it is not fresh in my mind). I think it is part of my buddie's collection and not hooked up to anything. You should have held onto yours...

[@Douglas_Blake_579]

@@vintageaudioreview _"You should have held onto yours..."_ Oh so now you tell me! (Grin). Yes I should have, it's a great piece of kit.

[@gino3286]

Hi thank you so much for your always great review I love the lab approach for testing equipment I have a question maybe trivial about noise at frequencies lower than the 1kHz test tone Can we say that it comes from power supply ? could it be the evidence of supply caps aged and not up to specs ? i mean can a main caps (the big ones) replacement provide benefits ? this is a 50 years old unit after all Probably caps are gone ?

[@vintageaudioreview]

Great question. The noise levels on this unit looked pretty good, which are basically the 60, 120,180hz "hum bars" from the power supply, and are predominately caused by the rectifier diodes and filter caps. If this were mine I would not replaced the filter caps as that noise level is pretty much on par with many other amps/intg amps, receivers and would not be very noticeable a few feet away from most speakers. The caps in the unit are not gone. There are folks who want to replace all of the electrolytic caps on something this old, and that is fine for them. I think I will do a video on that topic one day.......

[@gino3286]

@@vintageaudioreview hi thank you sincerely for the kind and helpful advice I asked because many times i have seen these spikes below the 1kHz tone in the THD test even at low power I have a sansui au6900 myself more or less of the same period The sound is fine I was just worried by the 50 years thing However the old rule applies Dont fix what is not broken Thanks a lot again

[@vintageaudioreview]

@@gino3286 Yeah, I subscribe to the "if it's not broken don't fix it" rule, unless you have something that is known to have a problem or you just want to feel better about the particular piece of gear.