Hi Jez.
I’ll do it this weekend. Cheers.
Interesting, I’ve had a couple of 34s here and basically wrote them off as total snooze fests, “a deadness to the sound” kind of sums up what I’ve heard.For me the rumble filter, or lack thereof, fixed a deadness to the sound. It just sounded a lot more dynamic and powerful.
Final mods done.
I don’t like the result: upper bass too prominent. It's a subjective thing. Better lower notes, perhaps, on organ music.
I see the dust protection mylars flap quite a lot!
Remember I only use ESL57s, nothing else.
The old 33 remains much better on phono.
The 34 sounds good but I have the feeling it could still fare better on phono. And please don’t get me started on op-amps lacking involvement, etc. Just not true!
I use Dreams a lot for testing and with the 34 I almost can’t hear the vibraphone which is so present and crystal-clear with the 33.
Once again I don’t get why all those Internet people say things like electronics have moved on, the 33 casts a veil on music, etc. Utter BS.
Dictators know the power of reading, don’t they. But I digress!
Final mods done.
I don’t like the result: upper bass too prominent. It's a subjective thing. Better lower notes, perhaps, on organ music.
I see the dust protection mylars flap quite a lot!
Remember I only use ESL57s, nothing else.
Once again I don’t get why all those Internet people say things like electronics have moved on, the 33 casts a veil on music, etc. Utter BS.
Oh yes but I do have other systems you know! I just thought the 34/405/ESL pair would be better than the 33/303/ESL.
But that's fine really! Thanks for your comments.
However the 33 was designed to work with the 303, not the 405.
The reason I asked is explained here
http://www.audiomisc.co.uk/57and303/interact.html
The output capacitor of the 303 interacts with the ESL57 to give a changed reponse as shown on the webpage. This will be absent using a 405. However the 33 was designed to work with the 303, not the 405. And the change in bass response isn't simple in form.
...though the 405 was designed to work with the 33, it wasn’t until years later that the 44 and finally 34 appeared.
But the difference between 303 and 405 when driving the ESL57 is the complication I was pointing out.
That said, I tried the ESLs with various amps and I never fried any.
I have a 34 and am considering your suggested mods but would like to question the change of c12 and c13 from 1.5uf to 2200uf is this correct as this seems to be an enormous change in value?Oh OK then...
For MM (all part numbers refer to schematic in post 25):
C12,13 = 100uF (on MM input board) Observe polarity.
R34 = 82K
C27 = 10uF
If you want to bring the slight treble boost down to something more correct make C21 150pF
It's a pretty weird design overall...
For MC:
C12,13 = 2200uF (on MC input board) Observe polarity.
R34 = 82K
C27 = 10uF
C18 = 220uF
Some of these values may seem counter intuitive in some ways.. or at least odd, but they are correct in sim and I have very little doubt that they will work in practice.
Do all or non of the above mods! There are some strange interactions, which I've taken care of.... I hope
I have a 34 and am considering your suggested mods but would like to question the change of c12 and c13 from 1.5uf to 2200uf is this correct as this seems to be an enormous change in value?