sorry to go off-topic with unbridled enthusiasm but you couldn't prise the LM4562's outof my dead hands now that they have really settled in! (thanks again Malefedo) My '67 really sings now and it doesn't have even half the mods I have read here.
I'm so please with these opamps that they are taking pride of place in a Tripath amp being rebuilt for me (surrounded by a bevy of admiring Caddock mk132's to keep them company)
I'm so please with these opamps that they are taking pride of place in a Tripath amp being rebuilt for me (surrounded by a bevy of admiring Caddock mk132's to keep them company)
poynton said:
Hi Andy,
Terimakasih......🙂 , I have been living in Samarinda since 1995, 150 km from 'oil city'. Now, I hear you will be going to NZ , oh you looks very busy but still have time for your marantz, great..😉
Hi Ray/Andy
I have checked again last nigt and seem ok for wiring and 317 input (16.10V), but I doubt the transistor (B547C) work unproperly, I will replace with a new one tonight.
Tks Ray, terimakasih Andy.
Regards
aquar
marantz 67 mods
Hi guys-thanks for info-Brent/Simon
the solder pad on right op-amp socket was destroyed by me on the process of removing the old one-Doh!!!
i have ran the wire link the track together-now both chanel s have music but it seems the high frequency is missing and sound really closed in-just wonder does this thing need to break in again? how long would it take?
also- what would be a cost efficient voltage regulator to replace the 79M12/78M12? Quan.
Hi guys-thanks for info-Brent/Simon
the solder pad on right op-amp socket was destroyed by me on the process of removing the old one-Doh!!!
i have ran the wire link the track together-now both chanel s have music but it seems the high frequency is missing and sound really closed in-just wonder does this thing need to break in again? how long would it take?
also- what would be a cost efficient voltage regulator to replace the 79M12/78M12? Quan.
Re: marantz 67 mods
Hi Quan,
I'm glad you've got sound in both channels once more! When you say the HF sound is missing, are you talking about a definate technical problem or more a sound quality problem?
If anything the LM4562 would sound a bit bright initially. Possibly a touch less bright after settling down, warming up, running in...
Perhaps one of the filter caps you changed is the wrong value and is rolling off too much treble. Can anyone help with a part suggestion here?
Simon
quan said:
Hi Quan,
I'm glad you've got sound in both channels once more! When you say the HF sound is missing, are you talking about a definate technical problem or more a sound quality problem?
If anything the LM4562 would sound a bit bright initially. Possibly a touch less bright after settling down, warming up, running in...
Perhaps one of the filter caps you changed is the wrong value and is rolling off too much treble. Can anyone help with a part suggestion here?
Simon
What is the dc offset of both channels now?
I agree with Simon, sounds like you have a cap in the wrong place.
I once changed the resistors and managed to swap the positions of a 10k and a 22k (i think) on one channel.
One channel sounded far duller than the other. Turned out that the problem channel was the one that sounded brighter.
I would check both channels and compare the component values to the schematic.
The caps around the op-amp btw.
Lee.
I agree with Simon, sounds like you have a cap in the wrong place.
I once changed the resistors and managed to swap the positions of a 10k and a 22k (i think) on one channel.
One channel sounded far duller than the other. Turned out that the problem channel was the one that sounded brighter.
I would check both channels and compare the component values to the schematic.
The caps around the op-amp btw.
Lee.
quan said:
Unfortunately I don't know which it would be, hence my asking for help from others. If you look in the service manual you can check values of the small capacitors and the resistors around the op-amps. I noticed in your photos you've changed some of these and one or two looked like rather large caps (physically)...
Simon
marant mod
Hi Simon-the output filter cap-original value is 100pF polystyrene but i could not find the smae component from Farnell in Australia thus i changed to Vishay 0.1UF polyester cap. , could this be the problem ?otherwise all the parts are as listed. Quan.
PS-still try to recover from this morning Liverpoolv Chelsea game.
The Dc offset are 22mV from both chanels now.
Hi Simon-the output filter cap-original value is 100pF polystyrene but i could not find the smae component from Farnell in Australia thus i changed to Vishay 0.1UF polyester cap. , could this be the problem ?otherwise all the parts are as listed. Quan.
PS-still try to recover from this morning Liverpoolv Chelsea game.
The Dc offset are 22mV from both chanels now.
Re: marant mod
Ahha, well 0.1uF is not the same as 100pF. It IS the same as 100nF though.
0.1uF = 100nF = 10000pF (i think 🙂 )
If you can't find a 100pF polystyrene, silvered/silver mica or polypropylene you should probably put the original orange coloured cap back in.
Are there any other parts in this area you changed for different values?
quan said:
Ahha, well 0.1uF is not the same as 100pF. It IS the same as 100nF though.
0.1uF = 100nF = 10000pF (i think 🙂 )
If you can't find a 100pF polystyrene, silvered/silver mica or polypropylene you should probably put the original orange coloured cap back in.
Are there any other parts in this area you changed for different values?
marantz mod
wow-this is fun, a day job and then night hobby-then lots of football- looks like another part order tomorrow.!!Quan.
wow-this is fun, a day job and then night hobby-then lots of football- looks like another part order tomorrow.!!Quan.
Re: marantz mod
Snooker's the only sport I watch. There was an Aussie that did quite well as it happened, but got knocked out by Ronnie O'Sullivan. Robertson.
quan said:
Snooker's the only sport I watch. There was an Aussie that did quite well as it happened, but got knocked out by Ronnie O'Sullivan. Robertson.
Guess what i have to buy 10 of 100pF PS cap from RS component for $4/each!!!!-are we kidding???-Like you say Simon ,i need to look for ALTERNATIVE-BTW THE old caps have already arrived at recycling bin.-no other parts are changed for a different value
Well i will be cheering on my team tonight! Come on utd!!
I have skippies lips already 😀
Brent
I have skippies lips already 😀
Brent
quan said:
Please take a moment to learn how to search for things on the Farnell website, they do have most parts.
Farnell link
In case the link doesn't work that's order code 9520015.
2.5% tolerance polystyrene capacitor, in stock, order multiple 1, $2.07.
Simon
I found that by searching for 100pf. This is the best way to search Farnell: start with one part of the specification, then select other parameters from the boxes, as they appear, to narrow down your selection. Be careful when soldering in any polystyrene caps, I gather they're sensitive to overheating.
Simon
Simon
