there is also some (if I remember OK) 3-LP album called "Chicago Blues".......compilation in fact ,in wallet-like envelope (remember sort of
red wax stamp in one corner).....
I have not it handy in this moment,so I can't give more references,but -that's awesome album
I like header of this thread;
in our endless (and more than anything-unsuccessfull) efforts to make Papa blush for even one moment , I have proposal to mods : make this thread sticky
GRollins said:
AHHH but that could be the new Pass Labs product! Sense around! you dint even have to drink the wine. as the amp heats up, the aroma of a nice vintage (insert expensive vintage wine type here) could waft through the air and to the listeners nose. Heck if that had been the 60's we would be talking about a different substance but thats anothe r topic all together.....
And Besides. I didnt say it had to be a GOOD wine. a nice bottle of Mogen David or Ripple would provide the same effect.
And besides, isnt there something terribly poetic about sacrificing a bit of the lifes blood over our hero's favorite parts anyway?
I wonder if Fets soaked in Wine and offered up to the gods would give an amp that nice warm round soft sort of sounding feeling?
I guess the bigger philisophical debate will be over Red V.S. White! and maybe that pertains to what sort of music you listen to?
When is it appropriate to use Rose' and Champange'
Do california grapes sound better then the french?
Hmmm, maybe we scrap all these big heatsinks and go with a liquid cooled amplifers that use wine as the coolant?
Oh oh, or, insulate all the exposed traces and submerge the PCB in wine. the chassis could be the wine tank and the amp can operate underwine. the next hi fi gimmick.
Hmm Wine filled speaker cables?
OHHH wine based ferrofluid for speaker VC gap cooling!
so many possibilities....
Zc
Zero Cool said:
AHHH but that could be the new Pass Labs product! Sense around! you dint even have to drink the wine. as the amp heats up, the aroma of a nice vintage (insert expensive vintage wine type here) could waft through the air and to the listeners nose. Heck if that had been the 60's we would be talking about a different substance but thats anothe r topic all together.....
And Besides. I didnt say it had to be a GOOD wine. a nice bottle of Mogen David or Ripple would provide the same effect.
And besides, isnt there something terribly poetic about sacrificing a bit of the lifes blood over our hero's favorite parts anyway?
I wonder if Fets soaked in Wine and offered up to the gods would give an amp that nice warm round soft sort of sounding feeling?
I guess the bigger philisophical debate will be over Red V.S. White! and maybe that pertains to what sort of music you listen to?
When is it appropriate to use Rose' and Champange'
Do california grapes sound better then the french?
Hmmm, maybe we scrap all these big heatsinks and go with a liquid cooled amplifers that use wine as the coolant?
Oh oh, or, insulate all the exposed traces and submerge the PCB in wine. the chassis could be the wine tank and the amp can operate underwine. the next hi fi gimmick.
Hmm Wine filled speaker cables?
OHHH wine based ferrofluid for speaker VC gap cooling!
so many possibilities....
Zc
why not little reservoir as in inkjet printers...sort of capilar soaking and pouring on hottest part of amp
refill after 6 months with favorite flavor........
hehe , talkin' about custom amps.......
steenoe said:Barchetta, I still cant send you the PDF. The email keeps bouncing back.
Zen Mod, that has to be an awesome albumI am really exploring the old blues guy's right now. They made a lot of great stuff.
Thanks to Mr. Pass, they never sounded better
Steen
Philosopher's Stone-Van Morison
everything from Sony Boy Williamson
Billie Holiday
list is really too long
jazz & blues.........life is joy,don't you think .........
Guys I apologize.. I was not being notified of replies.. I need to check and see whats going on in that regard..
to all who explained cascoding THANKS! I recieved the unit and it appears to be the old design.. I started a new thread because you guys have taken over mine .. heheh
Please look for my question about repairing this old guy.. its in rough shape.. but I think can be brought back.. My working unit does not say cascode design on the front so I assume it is not either.. this will be a great match I hope!
to all who explained cascoding THANKS! I recieved the unit and it appears to be the old design.. I started a new thread because you guys have taken over mine
.. heheh Please look for my question about repairing this old guy.. its in rough shape.. but I think can be brought back.. My working unit does not say cascode design on the front so I assume it is not either.. this will be a great match I hope!
Does anyone use Pass labs or First Watt Amps for powering AKG K1000 headphones
I have tried contacting Nelson Pass on his published email address several times and have never received a reply. Im not sure if the email contact quoted is still live, or if there may be a spam filter stopping my email getting through.
I hope some of the members might be using Pass Labs or First Watt amplifiers to drive the AKG K1000 headphones (and others)
The AKG 1000 impedance is pretty typical of headphones, at 120 ohms, but they require a lot of voltage (power) to get to a good listening level. They're rated at 1 watt maximum, which corresponds to 11V RMS, and at their stated efficiency of 74dB/mW, you need 400mW of drive to get to 100dB, which is a good target for a maximum listening level.
OTL tube amps can get close to this power level, but the problem is that the K1000's don't sound very good unless they're driven with a really low output impedance. They were designed to be driven by a "normal" power amplifier, with a Zo of only a few ohms. When you drive them with an amp that has, say, 30-50 ohms Zo, they sound very thin (especially in the bass).
After undertaking quite a lot of research i've concluded that one of the Nelson Pass amplifier designs should be ideal for my purposes, but which one? I hope that members might be able to advise on the best choice(s) from current and previous designs (pass labs, first watt production i.e. Aleph)
The primary use will be to drive top of the range headphones such as AKG k1000 which need to be powered direct from the speaker outputs. The K1000's need up to 10 watts to do them justice! It would also be great if I could use standard headphones such as AKG K701, Grado RS-1 etc with the unit, but these only require a few milliwatts to drive. If there is no high quality headphone socket, perhaps someone can suggest a device/method of connecting them without compromising the superlative qualities of the amplifer and of course protect the headphones from overload.
I see that some of the new frist watt designs like the F1 are power trans-conductance amplifiers with 10 watts output and the new AlephJ is an update of one of the legendary designs.
Regarding the preamp, would a preamp be required or would it be possible to use a source with a volume control as a preamp i.e. a CD player? (e.g. Wadia, Ayre, Emm Labs) If I require a preamp ideally it would have provision for optical as well as analogue XLR inputs , so that SACD and a DAC could be supported. Also as I live in the UK the equipment would need to support or be modified to support 230 volts. I have tried step up transformers but they always compromise quality.
I have tried contacting Nelson Pass on his published email address several times and have never received a reply. Im not sure if the email contact quoted is still live, or if there may be a spam filter stopping my email getting through.
I hope some of the members might be using Pass Labs or First Watt amplifiers to drive the AKG K1000 headphones (and others)
The AKG 1000 impedance is pretty typical of headphones, at 120 ohms, but they require a lot of voltage (power) to get to a good listening level. They're rated at 1 watt maximum, which corresponds to 11V RMS, and at their stated efficiency of 74dB/mW, you need 400mW of drive to get to 100dB, which is a good target for a maximum listening level.
OTL tube amps can get close to this power level, but the problem is that the K1000's don't sound very good unless they're driven with a really low output impedance. They were designed to be driven by a "normal" power amplifier, with a Zo of only a few ohms. When you drive them with an amp that has, say, 30-50 ohms Zo, they sound very thin (especially in the bass).
After undertaking quite a lot of research i've concluded that one of the Nelson Pass amplifier designs should be ideal for my purposes, but which one? I hope that members might be able to advise on the best choice(s) from current and previous designs (pass labs, first watt production i.e. Aleph)
The primary use will be to drive top of the range headphones such as AKG k1000 which need to be powered direct from the speaker outputs. The K1000's need up to 10 watts to do them justice! It would also be great if I could use standard headphones such as AKG K701, Grado RS-1 etc with the unit, but these only require a few milliwatts to drive. If there is no high quality headphone socket, perhaps someone can suggest a device/method of connecting them without compromising the superlative qualities of the amplifer and of course protect the headphones from overload.
I see that some of the new frist watt designs like the F1 are power trans-conductance amplifiers with 10 watts output and the new AlephJ is an update of one of the legendary designs.
Regarding the preamp, would a preamp be required or would it be possible to use a source with a volume control as a preamp i.e. a CD player? (e.g. Wadia, Ayre, Emm Labs) If I require a preamp ideally it would have provision for optical as well as analogue XLR inputs , so that SACD and a DAC could be supported. Also as I live in the UK the equipment would need to support or be modified to support 230 volts. I have tried step up transformers but they always compromise quality.
Odd that your email hasn't reached me - it seems that
everyone else's has.
In any case, the F1 does seem to have some popularity
with the AKG's but I have not experienced it for myself.
I expect that the F2 would also work, but the two products
have different signatures, the F1 being a 3rd harmonic and
the F2 being 2nd harmonic.
It is probable that you could get by with just a passive
volume control.
everyone else's has.
In any case, the F1 does seem to have some popularity
with the AKG's but I have not experienced it for myself.
I expect that the F2 would also work, but the two products
have different signatures, the F1 being a 3rd harmonic and
the F2 being 2nd harmonic.
It is probable that you could get by with just a passive
volume control.
Re: Does anyone use Pass labs or First Watt Amps for powering AKG K1000 headphones
To decide we may need some specifications.
74 dB SPL at 1 mW, is a lot lower than 'normal' phones
If I did my math correctly,
they would need to get a peak 100 dB SPL (+26dB) into 120 Ohm:
* 0.398 Watt !!!
* 6.91 Volt RMS, = 9.77 Volt Peak
* 57.6 mA RMS, = 81.4 mA Peak
Say 7 Volt RMS, and it would good if
a dedicated custom HeadPhones Amplifier for AKG K1000
had a voltage gain of like 10.
This would give an input sensitivity of 0.7 Volt RMS.
To produce absolute hifi at 81.4 mA peak output,
we may aim for a Class A output of 5-10 more.
Say an output stage Class A with idle Current: 400-800 mA.
And I would say like Voltage Gain ~10.
User manual: http://www.akg-acoustics.com/mediendatenbank2/psfile/datei/34/k1000_en_d4055c4b8dfd60.pdf
Service manual: http://www.akg-acoustics.com/mediendatenbank2/psfile/datei/34/k10004055d23c1050f.pdf
Regards
lineup
Complin said:
To decide we may need some specifications.
74 dB SPL at 1 mW, is a lot lower than 'normal' phones
If I did my math correctly,
they would need to get a peak 100 dB SPL (+26dB) into 120 Ohm:
* 0.398 Watt !!!
* 6.91 Volt RMS, = 9.77 Volt Peak
* 57.6 mA RMS, = 81.4 mA Peak
Say 7 Volt RMS, and it would good if
a dedicated custom HeadPhones Amplifier for AKG K1000
had a voltage gain of like 10.
This would give an input sensitivity of 0.7 Volt RMS.
To produce absolute hifi at 81.4 mA peak output,
we may aim for a Class A output of 5-10 more.
Say an output stage Class A with idle Current: 400-800 mA.
And I would say like Voltage Gain ~10.
User manual: http://www.akg-acoustics.com/mediendatenbank2/psfile/datei/34/k1000_en_d4055c4b8dfd60.pdf
Service manual: http://www.akg-acoustics.com/mediendatenbank2/psfile/datei/34/k10004055d23c1050f.pdf
Regards
lineup
Threshold 400A
A couple of years ago I found and successfully bid on an eBay listing for a 400a that had been salvaged from a metal scrap bin.
With the kind assistance of the folks in this forum (and some very helpful info from Nelson Pass), I was able to bring it back to life as the heart of my own home system.
I've been an audio enthusiast for over 40 years and have owned, auditioned, and restored hundreds of amplifiers. I'd have to say this is one glorious piece of engineering that I'll definitely enjoy growing old with!
I've included a "before" and "after" photo of the unit for your enjoyment.
Best regards,
Terry Keith
Restorer in OHIO
A couple of years ago I found and successfully bid on an eBay listing for a 400a that had been salvaged from a metal scrap bin.
With the kind assistance of the folks in this forum (and some very helpful info from Nelson Pass), I was able to bring it back to life as the heart of my own home system.
I've been an audio enthusiast for over 40 years and have owned, auditioned, and restored hundreds of amplifiers. I'd have to say this is one glorious piece of engineering that I'll definitely enjoy growing old with!
I've included a "before" and "after" photo of the unit for your enjoyment.
Best regards,
Terry Keith
Restorer in OHIO
Attachments
Complin,
the K1000 sounds great through Aleph amps, i expect a current amplifier may do even better.
Which seems to be confirmed by several tests i've read so far, but i'm still waiting for the gravy F1 board thread to show up.
My question is if you find it worth blowing 200 Joules a second for say 50 mW of continuous output power ?
The AKG can do with a reduced rail voltage Aleph amplifier, which raises the efficiency considerably.
Considering that you'll never need several amps of output current for a K1000, the number of parallel output mosfets on an Aleph amp can be reduced to a single device with the highest possible bias.
Which is unlikely to be feasable with either of the transy FWers.
You might consider constructing an F1 for the AKG, and a blazing hot Aleph Minimi for other headsets.
(utterly disappointed that no one responded to my suggestion of a 2-stage transconductance amp)
the K1000 sounds great through Aleph amps, i expect a current amplifier may do even better.
Which seems to be confirmed by several tests i've read so far, but i'm still waiting for the gravy F1 board thread to show up.
My question is if you find it worth blowing 200 Joules a second for say 50 mW of continuous output power ?
The AKG can do with a reduced rail voltage Aleph amplifier, which raises the efficiency considerably.
Considering that you'll never need several amps of output current for a K1000, the number of parallel output mosfets on an Aleph amp can be reduced to a single device with the highest possible bias.
Which is unlikely to be feasable with either of the transy FWers.
You might consider constructing an F1 for the AKG, and a blazing hot Aleph Minimi for other headsets.
(utterly disappointed that no one responded to my suggestion of a 2-stage transconductance amp)
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