ef stages are used since they are "forgiving" also since the market tends to go to always higher power systems cfp are not the best for it .....Now days i don't recall a real high power cfp on the market
Point is that to my understanding when the power is no more than 50-60 W and duty is casual listening cfp is the best ( at least the cfp i am listening to )
Th Japanese amplifiers for example had many cfp designs in the past .... i think that they stopped producing them only because efp was easier to handle
as said though this is just my opinion
Point is that to my understanding when the power is no more than 50-60 W and duty is casual listening cfp is the best ( at least the cfp i am listening to )
Th Japanese amplifiers for example had many cfp designs in the past .... i think that they stopped producing them only because efp was easier to handle
as said though this is just my opinion
MAT12
Hi Sakis,
What do you think about use of MAT12 instead Q1/Q2 pair?
http://www.analog.com/static/imported-files/data_sheets/MAT12.pdf
Regards,
Hi Sakis,
What do you think about use of MAT12 instead Q1/Q2 pair?
http://www.analog.com/static/imported-files/data_sheets/MAT12.pdf
Regards,
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well spec wise looks like a very fine option .... Bit worried about the low voltage though ( that will be on the risky side )
in an amplifier like that made so simple obviously choice of LTP and VAS will make all the difference .... Mat's is something i never did ...feel free to try and post your results here
kind regards
sakis
in an amplifier like that made so simple obviously choice of LTP and VAS will make all the difference .... Mat's is something i never did ...feel free to try and post your results here
kind regards
sakis
Yes, CFP seems to be more relaxed. But at first impression (which matter a lot in blind test) sonic is usually more favorable (by most).
I think my problem with CFP is in paralleling the output. A single pair output can easily achieve 50-60W which is enough for most circumstances, BUT paralleling is sometimes required not to increase the output power but to handle higher bias current, which usually is a design requirement for a better sounding amp.
??
I'm not a EE. What's the meaning of these abbreviations?
I have had the desire (for years) to build several of these awesome amps to upgrade/bi-amp all 6 channels of my HT setup; currently mix of Rotel, Belles, & Hafler XL280s. Can't $wing the test equipment, time, sourcing parts, or private space right now to do so. Keep doing what you do. You inspire the rest of us!
Thank you. Tony
My present P3A amp uses these tranistors at input stage fairchild q1q2q3-2n5551 vas stage hitachi q4-2sb469 q9-2sd669 driver fairchild q5-2sc2073 q6-2sa940 output toshiba q7-2sc1941 q8-2sc5198 . Over all the sound quality is great. It is very important to use the same manufacturer of transistor stage by stage to achieve a perfect match in your amplifier.
we have been through that many many times
the pcb i make is only for my personal pleasure ( under my changes and requirements also )
Feel free to make your own or choose from so many presented randomly in the forum ...
Probably though the best will be to get an original from ESP i am pretty sure that costs nothing
Kind regards
sakis
the pcb i make is only for my personal pleasure ( under my changes and requirements also )
Feel free to make your own or choose from so many presented randomly in the forum ...
Probably though the best will be to get an original from ESP i am pretty sure that costs nothing
Kind regards
sakis
well here is one amplifier that can be stand up very very properly next to the combo doz -P3A
Just a reminder the P3a is the one i make and the DOZ eventhough circuit is typically as seen in the ESP pages pcb , decoupling , distribution of power ground and signal is far more sophisticated .
Ladies and gents i think that the electrocompaniet EC2 sounds alike the P3a +doz after it has been repaired ,recaped , and slightly ( but very slightly modified )
bass is plenty tight and fast , quiet punchy for a class A thing ( Actually highly biased class AB ) there is speed ....air... sound stage ....Upfront and crystal clear middle while high is extremely clean , crisp and detailed .
i am amazed... i think i will be listening far more detail listening from this amplifier before i give it away to the costumer .
kind regards
sakis
Just a reminder the P3a is the one i make and the DOZ eventhough circuit is typically as seen in the ESP pages pcb , decoupling , distribution of power ground and signal is far more sophisticated .
Ladies and gents i think that the electrocompaniet EC2 sounds alike the P3a +doz after it has been repaired ,recaped , and slightly ( but very slightly modified )
bass is plenty tight and fast , quiet punchy for a class A thing ( Actually highly biased class AB ) there is speed ....air... sound stage ....Upfront and crystal clear middle while high is extremely clean , crisp and detailed .
i am amazed... i think i will be listening far more detail listening from this amplifier before i give it away to the costumer .
kind regards
sakis
Sorry for that ..i was actually busy writing down a tribute for the EC2 in a Greek forum ..
Except that the EC2 is a lower in power next to a P3A other than that there is absolutely nothing in the minus side for this machine .
Yet again the input selector formed with relays but not a shunt topology so crosstalk between sources is some issue But next to so nice sound ...just switch off the source that doesnt play .
Clever to have a relay to select between a 6db pre and a passive configuration so you have a very flexible amplifier ...
I wonder if someone performs this schematic made as a dual mono without the pre and with a huge power supply and a better even more audiophile approach on the implementation of the same circuit ...
I think i will try to study this equipment a bit more
Kind regards
sakis
1)I run my set with the volume pot In the input of the DOZ
This aspect though is because my everyday listening 6-12hours per day is with near field monitors an in low power so yes id like my DOZ directly coupled with my P3a and benefit from a few dynamics in low power more .
2) when potentiometer is used in the input so the output of the DOZ will produce a quiet big thump at start up ...in my case this is not a problem since the configuration is a preamplifier and a separated amplifier which i power one behind the other manuly with a bit of delay to avoid the thump .
In an normal situation and in your configuration( integrated amplifier) a pot wired between the output of DOZ and the input of the P3A will produce no thump as long as the volume pot is at 0 at power up
Finally as long as you produce an integrated amplifier you may as well not instal an input capacitor in the input of the P3A and as long that this one already exists in the output of the DOZ .
Pictures of your work is welcome here and also it could be nice to make tests on the DOZ regarding power supply and post your findings here or in the forum for other people to see and learn from .
Kind regards
sakis
This aspect though is because my everyday listening 6-12hours per day is with near field monitors an in low power so yes id like my DOZ directly coupled with my P3a and benefit from a few dynamics in low power more .
2) when potentiometer is used in the input so the output of the DOZ will produce a quiet big thump at start up ...in my case this is not a problem since the configuration is a preamplifier and a separated amplifier which i power one behind the other manuly with a bit of delay to avoid the thump .
In an normal situation and in your configuration( integrated amplifier) a pot wired between the output of DOZ and the input of the P3A will produce no thump as long as the volume pot is at 0 at power up
Finally as long as you produce an integrated amplifier you may as well not instal an input capacitor in the input of the P3A and as long that this one already exists in the output of the DOZ .
Pictures of your work is welcome here and also it could be nice to make tests on the DOZ regarding power supply and post your findings here or in the forum for other people to see and learn from .
Kind regards
sakis
I also prefer low level listening so this is a dilemma for me: either to make gain in DOZ lower (6dB perhaps) or to put a pot at the input. If I use pot between DOZ an P3A it is probably wiser to retain caps at output of DOZ to prevent any possibility of DC to the pot (and nasty noise it produces) and remove input cap from P3A.
If I put a pot at the input, the problem of turn on and off noise shall be solved as it is done in Cyrus series I and II: I shall use small transformer for preamp directly connected to mains, so when mains cable is connected preamp will be immediately on. Power switch shall be used only for big transformer for P3A so power amp section will be turned on with it after turn on noise of DOZ has passed. Only if there is electricity blackout turn off noise is possible.
I shall make pictures when it is done and post it here on the forum.
If I put a pot at the input, the problem of turn on and off noise shall be solved as it is done in Cyrus series I and II: I shall use small transformer for preamp directly connected to mains, so when mains cable is connected preamp will be immediately on. Power switch shall be used only for big transformer for P3A so power amp section will be turned on with it after turn on noise of DOZ has passed. Only if there is electricity blackout turn off noise is possible.
I shall make pictures when it is done and post it here on the forum.
here is another one ...
Nice idea could be ( for tone control lovers ) to add a tone control in the P3A designed geriatric style IE nested in the feedback chain ...
In the past this was very common but include the danger that the load will modulate vas through the feedback and with bad results in capacitive loads or long cables and so on .
It will probably also require some small increase of gain ...still if done with proper parts and calculations i think that it will produce nice sonics
Nice idea could be ( for tone control lovers ) to add a tone control in the P3A designed geriatric style IE nested in the feedback chain ...
In the past this was very common but include the danger that the load will modulate vas through the feedback and with bad results in capacitive loads or long cables and so on .
It will probably also require some small increase of gain ...still if done with proper parts and calculations i think that it will produce nice sonics