...................and no, I don´t have to be drunk to do such things
, I´m crazy by nature 
Cheers
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I´m using a AD823ANZ (yes Damon, is a ****
Off-set 0mVolt and 1,5mVolt.
NE5534 on gain 3-5 normal too, but why it needed if exist LT1468?
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Yes of course, it´s a very simple circuit consisting of 4 Transistors 2 caps and a couple of resistors.
Delay time is approx. 1,5 sec ( short, but time enough for PSU to settle to stable voltage), so typical power on pop won´t occur.
Threshold for DC protection is about +/- 0.5V, that means any DC above 0.5V (+ or -) caused by a fault will switch off the output relay immediately to protect the headphones ( and ears ).
Tomorrow I will post the schematic and some explanations. ( Sorry, but not time enough now)
jajaja it´s a funny game but sorry, I don´t spend more time with this. I want to try a Muses1 and Muses2
Probably it´s very expensive for this amp but I think that it may be worth the experience.
I don't use OpAMPs in final version.
For me 2V RMS (maximum output voltage from AD1853 DAC) to my simple headphones Sennheiser HD 558 like a blood from ears.p/s: I want to build amplifier for STAX ESL headphones.
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Yes, I said that at the beginning
Now I have 13 headphones amps.
PD and I have done two STAX amps
Headphones amps collection.
I had 5 amps for HP, 4 sold (as non perspective).
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An amazing number of hp amps, so you are very experienced on this topic.
Would you say that every amp has it´s own characteristic ?
Do you have a best sounding favorite ?
I have experience but I´m not an expert.
EHMO, yes.... if you change a OPA (or a cap...) on our Lehmann´s, Don´t you change your sound?
A RA1 don´t sound similar to a Dynahi or our own Lehmann, no?. At the sametime, a LCD2 sound very different with a Pass HA and with a Dylano.
I really like all, but I have predilection for the Beta22 and a OTL with 6C33B.
I think that not exist a definitive HA amp... and this is funny
EHMO, yes.... if you change a OPA (or a cap...) on our Lehmann´s, Don´t you change your sound?
A RA1 don´t sound similar to a Dynahi or our own Lehmann, no?. At the sametime, a LCD2 sound very different with a Pass HA and with a Dylano.
I really like all, but I have predilection for the Beta22 and a OTL with 6C33B.
I think that not exist a definitive HA amp... and this is funny
First I have to say that there are many ways to realize such a circuit, my goal was to keep it simple and to have only clean voltages on the amp board, so the circuit is supplied by regulated pos. rail. This has the disadvantage that the relay switches off not immediatelly after power off, it needs at least ca. 0.5 sec ( it depends on the value of psu caps and the current draw of the whole amp.circuits)
In a few words:
Power on delay time is determined by the time constant of R2/C1
T2 will pull down Vbe of T1 if pos. DC voltage exceeds ca.0.5V, T3 is doing the same for neg. DC voltage.
R4 (possibly not necessary) limits just the discharging current (C1) if T2/T3 switch.
I´m using +/- 17V supply for my amp, for different supply voltage some values have to be recalculated, also R1 might not be necessary with another relay.
For T1-T4 any small signal transistor will be sufficient with current gain of >400 ( C-types)
I used the whole circuit in each channel ( consequent dual mono), but it´s possible to use just the second relay contact for the other channel. But the DC protection circuit must be duplicated for the 2nd channel.
Yes blackdod, the search for the ultimate headamp will never end
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If you ask me....... - Yes, I´m curious about your circuit........Will publish scheme of my LBCL or not?
Not a BCL but...
...long over due update about something I wrote that I was going to do.
I dusted off, well almost lol, the second XP-7 board I have and did the "inductor mod".
I will replace the XP-7 board in my PC headamp with this to see if the simulated improvements translates in to real world ones.
Pics attached of cut traces and the mounted inductors.
...long over due update about something I wrote that I was going to do.
I dusted off, well almost lol, the second XP-7 board I have and did the "inductor mod".
I will replace the XP-7 board in my PC headamp with this to see if the simulated improvements translates in to real world ones.
Pics attached of cut traces and the mounted inductors.
Attachments
Hi.
Maybe it's too late to post reply here.. But I have few question... Can sombody help me??
I am building a new lehmann BCL clone, I bought bare PCB from aliexpress and already populated resisters and diodes.. I bought Takman metal film for signal path and vishay dale RN55 for the others. I know takman metal film is not not the best choice, i just wanted to try them. Usually I prefer panasonic FM or FR, but it's impedance is too low here, so I will go with LZX 470uF/ 35v for diamond buffer.for RF rejection, I already populated LCR's polystyrene 100pf, and I will buy vishay MKP1837 22nf for opamp bypassing. I haven't chosen the other capacitors, here is my question.
1. Vishay BC snap-in 4700/ 40v is around $9 now. I know it is very good, but it's too much expensive.
Alternatively, Nichicon KG Type-II 4700/ 35v is around $5 and mundorf MLytic 4700 / 40 is around $10 from Hificollective. Price is just double, and is there audible improvement if I use Mundorf compared to Nichicon gold tune?
2. I have read all replies here and old black/ gold silmic II and panasonic Purism is recommended for opamp decoupling. But I can't get any of those now.. Alternatively I am thinking ROHS compliance brown/ white silmic-II or nichicon KZ. Is there other good alternative for here??
3. For Cadj position, it seems tantalum is best choice, but I personally hate tantalum.. I am thinking polymer which provides lower ESR and higher ripple cpmpared to low ESR electro. Could it be good choice also??
4. I already bought 20pcs of each Fairchild BC560C, BC550C, BD139-16 and BD140~16. measured all 80 BJT's Vbe and Hfe.. I couldn't find good match.. For BC's I can match Vbe, but closest match of HFE has 10% margin. And BD's.. It is not possible to find any similar value.. But I still can match exactly same Vbe. OK I will just match Vbe for BD139/BD140 and forget about HFE..
But for BC550C and BC 560C, is it worth buy more and match them??
I've got B531/ 651mV and B526 / 651mV for BC550C and B489 / 651mV and B500 / 651mV for BC560C.
Sorry about too many questions and also for my bad English.
Maybe it's too late to post reply here.. But I have few question... Can sombody help me??
I am building a new lehmann BCL clone, I bought bare PCB from aliexpress and already populated resisters and diodes.. I bought Takman metal film for signal path and vishay dale RN55 for the others. I know takman metal film is not not the best choice, i just wanted to try them. Usually I prefer panasonic FM or FR, but it's impedance is too low here, so I will go with LZX 470uF/ 35v for diamond buffer.for RF rejection, I already populated LCR's polystyrene 100pf, and I will buy vishay MKP1837 22nf for opamp bypassing. I haven't chosen the other capacitors, here is my question.
1. Vishay BC snap-in 4700/ 40v is around $9 now. I know it is very good, but it's too much expensive.
Alternatively, Nichicon KG Type-II 4700/ 35v is around $5 and mundorf MLytic 4700 / 40 is around $10 from Hificollective. Price is just double, and is there audible improvement if I use Mundorf compared to Nichicon gold tune?
2. I have read all replies here and old black/ gold silmic II and panasonic Purism is recommended for opamp decoupling. But I can't get any of those now.. Alternatively I am thinking ROHS compliance brown/ white silmic-II or nichicon KZ. Is there other good alternative for here??
3. For Cadj position, it seems tantalum is best choice, but I personally hate tantalum.. I am thinking polymer which provides lower ESR and higher ripple cpmpared to low ESR electro. Could it be good choice also??
4. I already bought 20pcs of each Fairchild BC560C, BC550C, BD139-16 and BD140~16. measured all 80 BJT's Vbe and Hfe.. I couldn't find good match.. For BC's I can match Vbe, but closest match of HFE has 10% margin. And BD's.. It is not possible to find any similar value.. But I still can match exactly same Vbe. OK I will just match Vbe for BD139/BD140 and forget about HFE..
But for BC550C and BC 560C, is it worth buy more and match them??
I've got B531/ 651mV and B526 / 651mV for BC550C and B489 / 651mV and B500 / 651mV for BC560C.
Sorry about too many questions and also for my bad English.
The Mundorf ag will give an improvement over the other parts from my experience on low voltage devices like this. A tighter, lower, more pinpoint bass was the result.
A good discreet op amp for a reasonable cost is the Audiofeel 301, run very warm however.
I use the 47uf Silmic ARS on op amp decoupling and some 100uf/50v after the regulators, are available on auction sites. Also like the Russian k71-5 .01uf across the rails, under the op amp pins.
A good discreet op amp for a reasonable cost is the Audiofeel 301, run very warm however.
I use the 47uf Silmic ARS on op amp decoupling and some 100uf/50v after the regulators, are available on auction sites. Also like the Russian k71-5 .01uf across the rails, under the op amp pins.
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