Rotel 1072

[mouser830]

Has anyone modified a Rotel 1072 or know someone who may want to give it a shot, From my readings, it seems prime for upgrades , good drive, good power and architecture.

I have the basiv skills and desire but little experience on anything other than tube amps.

I am knew here and at the DIY thing but have been in Audio for over 20 years and am currently running a 300B setup.

Thanks

Scott

[Gasho]

I modified an older Rotel amplifiers (power and integrated) . I belive they have same topolgy as new ones. First of all Rotel amplifiers (and Cd players) have very good base for upgrade. If you have knowledge about electronic components I will try to give you some advices. It is not expesive upgrade but sonic improovements are quite large. First thing you can do here is to replace resistor that connect output stage and inverted input of power amp section by 30-50% larger value resistor of higher quality(Vishay/Dale 1>% tolerance). That one is in negative feedback rail and with larger value the amp works with smaller NF , but have larger gain and smaller damping factor. Secound thing is to replace all Black Gate (F type) caps in signal path, with BG-NX HI-Q types or MKP type of capacitors 2,2uF . Now when power amp section have greater gain , you can bypass line preamp section wich is made with OP amps (BB OPA-2604 I think) and connect power amp directly to volume control pot. If you succeed to do that , theres a chance that you use only one bypass cap between pot and power amp input. PS in Rotel is quite good so here is a little thing to do, exept to change rectifier bridges(greatz) with some fast power diodes. This is it. There are no big shanges in topology and makeing a new circuit boards . This is all about cleaning the signal path and makeing power amp section to produce less tehnical and more musical sound.

[Gasho]

OOuu **** , that is the CD player . OK latter i will try again You forget to write >RCD< before 1072

[mouser830]

Thanks for the information, I am sorry, yes it is a RCD1072.

Scott

[Gasho]

Do you want to leave basic topology of player intact? Yo can upgrade all power supplyes and analog section with specific elements of higher quality. Picture: Schottky diodes as rectifiers. Instead of usual 1N4005-7

[Gasho]

This is my Rotel RCD990, but the same principle of upgrade is in your cd player. You only must find points in layout where these components are. Picture: Sanyo OS-CON caps(puple)(6,3V 150uF) instead of Black gates/Wima MKP in digital filter and D/A converter chip PS rails +/-5V

[Gasho]

Change the OP amps in your analogue section. You can use AD825 (SMD mono chip) or better. Look around forum, there must be discussion about sonic quality of different OPs.

[Gasho]

Change output caps with better quality MKP types like Mundorf, Infinycap....

[roibm]

Gasho, very nice quality pcitures.
I have two questions tho:
- where do you get your OS-CON?
- what do you put on top of those caps? it looks like some sort of "grease"

[Gasho]

I buy OS-CONs from Farnell. I Have catalog and itœ full of nice components for upgrade and DIY. There is nothing on top of OS-CONs, but BGs have layer of gummy like glue, nothing special .