Today I had a big surprise when opening my 101 pre amp..!!!
I am surprised and a quite troubled because before opening the case, I have been studying a 101 schematic I downloaded from here: http://www.doebbe.com/hifi/items/meridian101.html
The worst part is that I used the pictures and the schematics from this site to ask my friends about advise on recaping..
In reallity, my 101 is very different and instead of using a discrete input buffer, it has a NE5532 opamp
So, here I am again, trying to get information on how to improve this machine.
The good part is that the MM input module and the RIAA do not seem to have any opamps.
I can not open the boxes but I am posting some pics so anyone can see.
(The MC phono module I have in place is not as good sounding as the MM modules on the right of the picture, I was only experimenting. )
I must avoid the opamp in the input buffer, so I am connecting my CDP to the tape input that has 20kohm inpedance hoping it is compatible with the CD53 DOS output impedance.
Another good thing is that this 101 has a balanced output... not like the one in the schematic.
There are Tantals in the signal path.... very old style thing indeed.
Ricardo
I am surprised and a quite troubled because before opening the case, I have been studying a 101 schematic I downloaded from here: http://www.doebbe.com/hifi/items/meridian101.html
The worst part is that I used the pictures and the schematics from this site to ask my friends about advise on recaping..
In reallity, my 101 is very different and instead of using a discrete input buffer, it has a NE5532 opamp
So, here I am again, trying to get information on how to improve this machine.
The good part is that the MM input module and the RIAA do not seem to have any opamps.
I can not open the boxes but I am posting some pics so anyone can see.
(The MC phono module I have in place is not as good sounding as the MM modules on the right of the picture, I was only experimenting.
)I must avoid the opamp in the input buffer, so I am connecting my CDP to the tape input that has 20kohm inpedance hoping it is compatible with the CD53 DOS output impedance.
Another good thing is that this 101 has a balanced output... not like the one in the schematic.
There are Tantals in the signal path.... very old style thing indeed.
Ricardo
Attachments
Long long time ago.... I had several B&O amps... in that time I already was into modding... and in those prehistorical eras, tants appeared... and I read about tem and... Well, I used to put tants in signal lines replacing polar EL.
Maybe there is some reason to that after all.
Ricardo (full on)
Maybe there is some reason to that after all.
Ricardo (full on)
Looks quite cool and fairly old-school Ricardo. The smoothing caps will want changing as much as any lol. If that 5534 is the input buffer then a 4561 would be a nice improvement for sure.
I don't know about the balanced output.
Tants are meant to be poor, so there's an easy upgrade - think Mundorf MKP.
Simon
I don't know about the balanced output.
Tants are meant to be poor, so there's an easy upgrade - think Mundorf MKP.
Simon
Re: Meridian 101
Simon, I know you built one of those... can you point me in the right direction ?
PS:
After seeing the opamp on the input buffer, I changed the setup and now the CDP is connected to the Tape input (not buffered).
The sound was a little thin at the begining but after some hours, I find it more detailed and with better dynamics.
Soundstage width is very good also.
I will recap the psu, replace the diode bridge by some 11DQ10 and use some +-15v spowers.
Hope I can replace the tants with BG NxiQ also. (Mundorf MKP are too big)
Will report the damages next week.
Ricardo
hotiron said:Hey Ricardo I had one of these years ago my one was pure discrete modules.
IMHO you should junk this old dinosaur and build your own pre amp.LOL
No I'm serious
Well, before I opened the case, I believed that my 101 was the original discrete one... Now I believe that a DIY discrete can be so much better.SimontY said:
Simon, I know you built one of those... can you point me in the right direction ?
PS:
After seeing the opamp on the input buffer, I changed the setup and now the CDP is connected to the Tape input (not buffered).
The sound was a little thin at the begining but after some hours, I find it more detailed and with better dynamics.
Soundstage width is very good also.
I will recap the psu, replace the diode bridge by some 11DQ10 and use some +-15v spowers.
Hope I can replace the tants with BG NxiQ also. (Mundorf MKP are too big)
Will report the damages next week.
Ricardo
I'm sure you can have some fun and get great sound from the Meridian. Contact our good friend Lee/Thomo if you want to try discrete, I'm sure he can sort you out with a cheap kit of all the right parts and a PCB. He and I both use the same buffer and love it. His is on boggo regs and sounds great. Mine is on SPowers and is therefore cleaner, brighter and more detailed. Very simple and easy circuit.
Simon
Simon
Thank you Andy
I read Lee has almost finished the Salas RIAA board.
I also finished reading about the Pass B1 buffered pre. Amazing simplicity and works on 2sk170 Jfets. (Just one JFET operated as follower transistor and a lower one acting as a constant current source formed by simply attaching the Gate pins of the JFETs to the Drain pins)
The circuit seems to be reasonably imune to PSU noise and you can read: "simple no-feedback circuits have tremendous clarity if the circuit has wide bandwidth and really low distortion"
Simon
Can you post a schematic for your buffer so I can compare with this one ?
Regards
Ricardo
I read Lee has almost finished the Salas RIAA board.
I also finished reading about the Pass B1 buffered pre. Amazing simplicity and works on 2sk170 Jfets. (Just one JFET operated as follower transistor and a lower one acting as a constant current source formed by simply attaching the Gate pins of the JFETs to the Drain pins)
The circuit seems to be reasonably imune to PSU noise and you can read: "simple no-feedback circuits have tremendous clarity if the circuit has wide bandwidth and really low distortion"
Simon
Can you post a schematic for your buffer so I can compare with this one ?
Regards
Ricardo
This is the probable origin that I find more plausible: "I’ve seen for the origin of the term is that it’s a corruption or variant form of box-standard, for something that is just the way it comes out of the box, with no customisation or improvements. "
Heavy stuff English Language is, Gentlemen !
Heavy stuff English Language is, Gentlemen !
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.