Maybe You can use similar topology as krell ksa 100.
Few examples bellow + diamond amp I have made recently.
For two first stages maybe it would be handy to use ccs instad of zeners supplies ?
Or idea nr 2:
-j-fet differential amps (I have used them even in ax11/sansui amp with no changes in circuit)
-bjt differential amps
-Vas
-driver
-output stage
One question, why 4 differential amps ? Two amps (as ksa100) + predriver+vas+driver+output stage should be good too.
Few examples bellow + diamond amp I have made recently.
For two first stages maybe it would be handy to use ccs instad of zeners supplies ?
Or idea nr 2:
-j-fet differential amps (I have used them even in ax11/sansui amp with no changes in circuit)
-bjt differential amps
-Vas
-driver
-output stage
One question, why 4 differential amps ? Two amps (as ksa100) + predriver+vas+driver+output stage should be good too.
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'Diamond circuit' or 'diamond amp' is amplifier with diamond buffer on input stage?
KSA100 is simple symmetrical amplifier, it's slow with high THD, I want made low TIM amp with high SR... Input stage in HD50 work with +/-15V rail I add another gain stage (diamond differential) with gain 20X to drive VAS...
Why your diamond amp use current divider instead multiplier in VAS?
Thank you Apex for all you do for audio. Thanks for posting. Just a few quick ones
Are you using +-45V rails ? . I suppose diamond stands for in house name of this amplifier?
kind regards,
Harrison.
HD50 will use +/-45V rails if I made it
Regards
Last edited:
Hi Mr Mile,
So here we start the HD-series amp... by Apexaudio
there will be 3 variants (I'm guessing)
HD-50, HD-100, & HD-200
Why not the BC550-560 for input LTP?
& cascaded if more higher voltage is used?
There will be HD50, HD150 and HD300.
BC550/560 can be use for LTP and many others transistors, no need to cascaded, LTP rail is +/-15V. There will be cascode in DD and VAS for higher rails.
Regards
Mile
I just was wondering if there is anythink special in diamond topology, diamond buffers are all over the net, so I just added 2 current sources and tef stage into it and it worked just fine and is simple. The results are there SR around 60u/us and thd nearly not mesurable:
http://www.diyaudio.com/forums/solid-state/240848-bg3-diamond-amp-simple.html
I was thinking how to improve the input stage but I have lack of knowlage and ideas.
Your amp is very interesting, buffored front stage is really good idea (I will defenetley build it).
There is one think that I do not know how to explain, I did listening tests of 2 nearly same circuits (one has toshibas TO92-mod second has 2n5xx1 tranies), there was audiable diffrence heard strigt away in bass area, the one with 2n5xx1 was bit deeper and more soft.
Another think - I just had changed 2 resistors in second diamond stage (reducing biasing by 50%) and harmonics character has changed totally - I do not know if this is specyfic case of my circuit or kind of diamond topology characteristics. It looks like that there is a way to fine tune the amp with listening test.
In your amp prapobly there will be a way too to fine tune the amp with listening sessions. I would put j-fets at input buffer anyway.
I just was wondering if there is anythink special in diamond topology, diamond buffers are all over the net, so I just added 2 current sources and tef stage into it and it worked just fine and is simple. The results are there SR around 60u/us and thd nearly not mesurable:
http://www.diyaudio.com/forums/solid-state/240848-bg3-diamond-amp-simple.html
I was thinking how to improve the input stage but I have lack of knowlage and ideas.
Your amp is very interesting, buffored front stage is really good idea (I will defenetley build it).
There is one think that I do not know how to explain, I did listening tests of 2 nearly same circuits (one has toshibas TO92-mod second has 2n5xx1 tranies), there was audiable diffrence heard strigt away in bass area, the one with 2n5xx1 was bit deeper and more soft.
Another think - I just had changed 2 resistors in second diamond stage (reducing biasing by 50%) and harmonics character has changed totally - I do not know if this is specyfic case of my circuit or kind of diamond topology characteristics. It looks like that there is a way to fine tune the amp with listening test.
In your amp prapobly there will be a way too to fine tune the amp with listening sessions. I would put j-fets at input buffer anyway.
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