then They turned up so popped them in some sockets today - 😎 safe to say the soundstage is huge with these in and imaging is much better.
Would be interesting to know whether the bipolar 02 could achieve the same or better results - whether a cheaper option could provide the same benefit - or whether the results are solely from changing from a bipolar to a fet 😕
Would be interesting to know whether the bipolar 02 could achieve the same or better results - whether a cheaper option could provide the same benefit - or whether the results are solely from changing from a bipolar to a fet 😕
You sound pleased 🙂
I nearly mentioned that you should try the decades old TL072 but to even mention that on here is just so damaging to ones reputation 😀 You just might be surprised though just how good these can sound.
I think you are just liking the 'fit' of a JFET based input stage in the relatively noisy environment they have to work under which really means the type of signals they have to deal with.
The OPA2604 (these were discontinued a while back) was another outstanding device for this type of application. Any you see now could well be fakes.
I nearly mentioned that you should try the decades old TL072 but to even mention that on here is just so damaging to ones reputation 😀 You just might be surprised though just how good these can sound.
I think you are just liking the 'fit' of a JFET based input stage in the relatively noisy environment they have to work under which really means the type of signals they have to deal with.
The OPA2604 (these were discontinued a while back) was another outstanding device for this type of application. Any you see now could well be fakes.
Indeed 🙂 It's a large improvement but I'd be keen to try out more types to see whether the same benefits could be had using lower cost parts.
Will keep my eye out for genuine examples of the parts you've mentioned and let my ears decide 🙂
If I am not wrong, HDAM module uses great j-fet transistors 2SK369-BL. HDAM module is great discrete j-fet opamp, something like Burson, but better. There is no need to bypass great j-fet discrete opamp, which is HDAM module, just to use another j-fet opamp. I only have schematic of HDAM module in CD57/67, but I presume that HDAM module in CD63 is the same.
Source for opamps
To eliminate getting fake parts order from an electronic parts dealer. Mouser, Farnell, Newark, and others buy from the legit manufacturer. They sell quality to buyers who order 1,000’s. Luckily they also tolerate hobbyists who order quantity 2.
I like Marantz disc players. Owned several, mainly SACD players. They had HDAM circuits too. Always left alone. Those are discrete like the opamps you subbed in.
A friend who had really good evaluating skills used to modify the HDAM power supply and change the bias current running through the HDAM’s. This is a simple resistor change. With all the work people did to the 63 it should be detailed. He said it is fidgety work, tightly packed small parts.
He felt this way better dealt with the noise on signal and voltage supply lines.
To eliminate getting fake parts order from an electronic parts dealer. Mouser, Farnell, Newark, and others buy from the legit manufacturer. They sell quality to buyers who order 1,000’s. Luckily they also tolerate hobbyists who order quantity 2.
I like Marantz disc players. Owned several, mainly SACD players. They had HDAM circuits too. Always left alone. Those are discrete like the opamps you subbed in.
A friend who had really good evaluating skills used to modify the HDAM power supply and change the bias current running through the HDAM’s. This is a simple resistor change. With all the work people did to the 63 it should be detailed. He said it is fidgety work, tightly packed small parts.
He felt this way better dealt with the noise on signal and voltage supply lines.
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Try a TL072. They were the darling of the audio world way back in the mists of time.
Nowadays it is fashionable to deeply criticise them over a couple of points that tbh don't really matter here.
They have limited drive ability (2k minimum for full voltage swing) which means they can not drive 600 ohm load fully... but does that matter when the levels in a player are only around 2 vrms.
They will easily drive 600 ohms at those kind of levels (and a lot higher) if needed.
Secondly they have a weird phase inversion characteristic (when misused) and you took the inputs beyond their specified common mode range, something that you would never see in applications like these.
So try 'em I say 😉 They cost buttons but make sure you get genuine devices from a recognised supplier.
While this is true, I’m not aware of it being possible to bypass the opamps entirely and just use the HDAM. Most seem to report better results from 1 good opamp than 2 good ones in series but might be a personal preference thing?
I normally do order from Mouser in “batches” to get the free shipping over £33 - didn’t realise they sold the ones in question still! Modifying the HDAM rather than bypassing it entirely like 99% of people do might be an interesting listening experience.
Will do 🙂 I’m sold, I’ll get some ordered next time I do an order from them. Then commence the 50p vs £40 opamp challenge 😀