Marantz Model 9 ~ Deep Dive ~ Restoration Review & Bench Tests
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- Опубликовано: 27 июл 2024
- In this video I review some history behind the iconic Marantz 9 amplifier along with a front panel control overview, a detailed look at the restoration that I performed, along with bench tests to verify that restoration.
Apologies for accidentally posting a picture of a Marantz 7T in the history section.
00:00 Introduction
00:46 History
03:59 Design Elements
05:20 Front Panel Controls
09:11 Adjustments
12:43 Tubes and Triode/Ultralinear Switch
15:34 Alternate Marantz 9 Versions
16:30 Restoration Review
36:19 Bench Testing
37:00 Ultralinear Output Power Test
39:18 Triode Mode Output Power Test
40:29 Frequency Response Bode Plot
45:52 Alternate Ways of Looking At Frequency Response
48:23 Phase Switch
49:20 THD Measurements
References:
audiohistory.com/files/docume...
www.hifiengine.com/
worldradiohistory.com/Archive... 
Развлечения
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Just gorgeous, timeless classic. Reason I keep my 1200B last one made in USA. Very informative video! Lots of cool tools there.
Great work Ben! Really enjoyed watching this video thank you very much.
interesting video. The u1f film cap bypassed with multiple smaller caps is quite common today. Several of the high end tube manufacturers now do this.
Beautiful pieces. What a privilege to get to work on them and bring back their original sound and features with modern parts. Please tell me that you played your favorite music through them for two days straight after verifying their power output. 🙂
Wow Ben EXCELLENT EXCELLENT THOROUGH description and work done on the 9 !!! Those are sure fine examples of those older beautiful amps , bet they sound as good as they look .
Scott -Kansas City
Yes they do!
I think I will try them out on the weekend!
The gain control on these was never meant for a source to be connected directly to the amplifier. It is a linear pot for one thing. For the best signal to noise ratio the manual indicates it is best to always keep the gain at maximum. The control is particularly useful when checking or adjusting bias and also to protect the amplifier and speakers when connecting a preamp for the first time or a device that might be noisy or have DC at the output...
Thanks for that
Thanks for this Video! ...I have a pair of these Monoblock Amps that I inherited from an old friend of my Dad's ...He thought that an output transformer was faulty, which turned out to be aged Electrolytic Caps in the Power Supply. I really need to dig these amps out of storage where they have been for almost a decade. I want to go thru the amplifiers and replace all faulty or failing components like you have just done in the video.
Nice work!
Really enjoyed this video!
Quite possibly the most comprehensive presentation of any vintage piece of tube audio gear that I have ever had the pleasure of viewing!
What brand were the output tubes?
Did you know the date of manufacture for each unit?
Perhaps you already know this, but with the 8-B, the factory date of manufacture was often stamped on the reverse side of the bias meter housing, hidden beneath the brass retaining strap.
Again, thanks!
I am glad that you enjoyed watching the video. Thank you for the tip on the manufacturing date. I will keep that in mind for future documentation when 1960s Marantz amps come in. Finding two matched quads of NOS EL34 was going to be tricky, it either take a lot of hunting or a lot of $$$. After speaking with the owner, we settled on current production EL34EH, the Electro Harmonix with the green label. Those are the tubes that were loaded during the bench testing.
all the PSU caps should be replace now reaching the end of there life i have 2 units repairing now
Yep, I replace all electrolytics on these by default.
@@NovaluxStereophonicI have a pair on the the bench now bias issues I'm fixixing