Hello
There is kit to build EHHA rev A amp from Glass Jar Audio.
Anybody with experience with that kit, can to tell me if transformators supplied with kit are good for 230-240V 50Hz mines ?
I`m going to use that amp with LCD-3. To my eyes EHHA should be OK with these phones. Any thoughts or suggestions about good amp for LCD-3 are welcome.
There is kit to build EHHA rev A amp from Glass Jar Audio.
Anybody with experience with that kit, can to tell me if transformators supplied with kit are good for 230-240V 50Hz mines ?
I`m going to use that amp with LCD-3. To my eyes EHHA should be OK with these phones. Any thoughts or suggestions about good amp for LCD-3 are welcome.
I don't think it has the required 'drive' to successfully match up with the LCD-3s - I tried to run my AKG k701s with it and is seemed to just run out of 'push' but those headphones do like a high current output stage, so maybe this experience isn't applicable to your situation
I used a much bigger R-Core transformer for this EHHA amp, 80 VA from China with a dc trap and primary voltage 'dropping resistor' - it worked extremely well, and matched up well with the Senn650s and the 800s and surprisingly, the Beyers too.
I'd suggest you look towards the F5 headamp to fully match up with the planar headphones - this is an active project and perhaps ask your question there as I think a couple of the contributors are using similar 'phones
I tried just plugging a couple of this type of 'phones straight into the juma version of the F5 and it worked very well indeed - used a valve buffer in front to add that characteristic, as I like this type of 'coloured' sound.
I used a much bigger R-Core transformer for this EHHA amp, 80 VA from China with a dc trap and primary voltage 'dropping resistor' - it worked extremely well, and matched up well with the Senn650s and the 800s and surprisingly, the Beyers too.
I'd suggest you look towards the F5 headamp to fully match up with the planar headphones - this is an active project and perhaps ask your question there as I think a couple of the contributors are using similar 'phones
I tried just plugging a couple of this type of 'phones straight into the juma version of the F5 and it worked very well indeed - used a valve buffer in front to add that characteristic, as I like this type of 'coloured' sound.
Yes, the F5 juma version - IMO, the best sounding one - using triple 2013/313s and less f/back - specific resistors, power supply - a rather good amp but not cheap anymore.
Not sure why the EHHa didn't/wouldn't drive the k701s well - it's not a power problem but it just lost clarity and bass when pushing the higher volumes and transients - increased the bias but didn't fix problem, changed the gain, etc but couldn't fix it, so just figured it was a problem outside my ability and went back to my DAO high current buffer - I use the k701s for a reference for my main system, but with bass extension - I'm not the smartest with electronics so this might be not at all connected to matching up the EHHA with your LCD-3s
The Beyers were quite a bit muffled, a bit thick in the bass/mids sound, even when rewired with the silver/copper lirz wire, unlike with the Bijou amp that's 'more musical' to me.
Not sure why the EHHa didn't/wouldn't drive the k701s well - it's not a power problem but it just lost clarity and bass when pushing the higher volumes and transients - increased the bias but didn't fix problem, changed the gain, etc but couldn't fix it, so just figured it was a problem outside my ability and went back to my DAO high current buffer - I use the k701s for a reference for my main system, but with bass extension - I'm not the smartest with electronics so this might be not at all connected to matching up the EHHA with your LCD-3s
The Beyers were quite a bit muffled, a bit thick in the bass/mids sound, even when rewired with the silver/copper lirz wire, unlike with the Bijou amp that's 'more musical' to me.
I found this one http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-9.html
and kit:
http://www.ebay.com/itm/2-X-DELUXE-...190?pt=LH_DefaultDomain_0&hash=item27e4f01296
Is that you mentioned ?
Others thoughts are still welcome.
and kit:
http://www.ebay.com/itm/2-X-DELUXE-...190?pt=LH_DefaultDomain_0&hash=item27e4f01296
Is that you mentioned ?
Others thoughts are still welcome.
or it is probably this one http://www.diyaudio.com/forums/pass-labs/210538-f5-bjt-input.html
if such, there is a another question. I tried to simulate that amp, and found that output is not to symmetrical. If I setting input signal to 1V, output is from -1.27 to 1.1V
if such, there is a another question. I tried to simulate that amp, and found that output is not to symmetrical. If I setting input signal to 1V, output is from -1.27 to 1.1V
No, not that one
The one I was thinking about is known as "F5 Headamp ?" on diyAudio - a guy called Sika is developing a pcb for it now - Patrick's design
I'm not sure if the Marsh headamp will be 'heavy duty' enough to drive your planar phones - there's a pretty complete thread on this one too
There's quite a few headamps devoted to low impedance loads and some of these could be up to the job - there's a couple of 'mini Aleph' type classA amps that will deliver a couple of watts.
Most of the readymade/kits from sites like "jim's Audio" are pretty much 'guesswork' projects - some work out quite well but others are mostly a waste of money, effort, etc - a bit of a lottery.
I did hear those phones with the top Cavalli headamp and it was pretty darn good, in anyone description, but the amps are over A$6k out here - curiously, I thought those also crazy priced JPL headphones were so colourless that they sounded dull at first - it seems to take a few minutes for the ears to adjust and appreciated the lack of any colouration - ugly heavy things, but I could live with them!
Personally, I think that if you're going to build your own amp for these phones, you could raise your sights a bit and aim for a better quality amp than the EHHA, with dedicated supply, etc
All the best ...
The one I was thinking about is known as "F5 Headamp ?" on diyAudio - a guy called Sika is developing a pcb for it now - Patrick's design
I'm not sure if the Marsh headamp will be 'heavy duty' enough to drive your planar phones - there's a pretty complete thread on this one too
There's quite a few headamps devoted to low impedance loads and some of these could be up to the job - there's a couple of 'mini Aleph' type classA amps that will deliver a couple of watts.
Most of the readymade/kits from sites like "jim's Audio" are pretty much 'guesswork' projects - some work out quite well but others are mostly a waste of money, effort, etc - a bit of a lottery.
I did hear those phones with the top Cavalli headamp and it was pretty darn good, in anyone description, but the amps are over A$6k out here - curiously, I thought those also crazy priced JPL headphones were so colourless that they sounded dull at first - it seems to take a few minutes for the ears to adjust and appreciated the lack of any colouration - ugly heavy things, but I could live with them!
Personally, I think that if you're going to build your own amp for these phones, you could raise your sights a bit and aim for a better quality amp than the EHHA, with dedicated supply, etc
All the best ...
http://www.diyaudio.com/forums/headphone-systems/211394-marsh-headphone-amp-linear-audio.html
PCB with matched semis and passive parts is $54 at Jack @ Tech DIY. Add a +/-15VDC supply (I first used a DC-DC switching supply with a wall wart). This was my end game amp with LCD-3C (45 ohm) and LCD-3F (110 ohm), before I moved on to electrostatics.
PCB with matched semis and passive parts is $54 at Jack @ Tech DIY. Add a +/-15VDC supply (I first used a DC-DC switching supply with a wall wart). This was my end game amp with LCD-3C (45 ohm) and LCD-3F (110 ohm), before I moved on to electrostatics.
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It's inexpensive to give it a try.
No signal capacitors, no NFB, thermally DC stable without a servo. Small parts count. Inherently ultra low distortion. Everything is there for a purpose and nothing else. I retired my DIY PP 6V6 headphone amp with silver OPTs after I built the Marsh.
I don't see where the Marsh has a high output impedance, it was designed to drive 32 ohm headphones. It drove my LCD-3C just as we'll as my LCD-3F.
No signal capacitors, no NFB, thermally DC stable without a servo. Small parts count. Inherently ultra low distortion. Everything is there for a purpose and nothing else. I retired my DIY PP 6V6 headphone amp with silver OPTs after I built the Marsh.
I don't see where the Marsh has a high output impedance, it was designed to drive 32 ohm headphones. It drove my LCD-3C just as we'll as my LCD-3F.
According to schematic, there is 4Ohm resistor above and below output semiconductor.
There is 16 Ohm resistor above pre output stage. Go math. If to replace transistors with wire: 16*4/(16+4)=3.2Ohm, add 4Ohm res to output=7.3Ohm total.
It's still Ok for 100+ Ohm load. But in general,good amps that designed to drive low impedance load, are low output impedance .
There is 16 Ohm resistor above pre output stage. Go math. If to replace transistors with wire: 16*4/(16+4)=3.2Ohm, add 4Ohm res to output=7.3Ohm total.
It's still Ok for 100+ Ohm load. But in general,good amps that designed to drive low impedance load, are low output impedance .
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Project Ember High Powered Tube Hybrid Headphone Amplifier and Pre Amp
Anyone have experience with that amp ?
Anyone have experience with that amp ?
Some EHHA rev A impressions.
Well, the EHHA rev A kits from glass jar audio are assembled and tested.
First of all, there was mentioned, that EHHA has not enough **** and vinegar to drive LCD-3...
Creative ZX @ 0dB (4.3 V amplitude) 1kHz -> EHHA rev A -> 110 Ohm resestive load-> Tektronix THS720A DSO.
Output voltage amplitude measured so "low" as 38V
. 4.3V is a maximum for my soundcard, so now I unable to find when the EHHA clipping begins. Simple calculation for output power available for an LCD-3 is :
P=U^2/R -> (38/2)^2/110 = 3.28W
The recommended amp for an LCD-3 is 1-4W capable. And yes, in "subjective" tests EHHA drives LCD-3 to the ear splitting levels without signs of an overload.
The kits from Glass Jar audio - there is no place for complains. All parts and PCB's are excellent quality. Assembly of EHHA is very simple, the setup procedure - set heater voltages to 6.3V, than set trim pots on amp board to middle position, apply power, check output zero, than set the current of an output devises, let the amp to heat up, finally adjust the current. Amp is ready for Rock'n'Roll The EHHA runs hot at class A, so enclosure with the good ventilation should be considered.
Now how it sounds. In the two words - JUST GREAT. Everything is here: deep and tight bass, clear, airy terrible, beautiful middle. There is not heavy "tubey" coloration, sound is neutral, very involving, with the little, gentle touch of tube's signature. The sound is very clear, good detailed. Due to impressive output power, there is no problems with the dynamics. I can to listen to my EHHA - LCD setup an hours without any sign of fatigue. The noise floor is very low for the tube containing amp. Of course it's not an O2, but the hiss is on the threshold of audibility in very quiet environment only.
I'm happy with that setup. Of course I'll try another amps, but I think it will be hard to beat outstanding performance of the EHHA.
Now the some comparisons. I have O2 modified to use LME49990 at gain stage, and Lehmann Cube clone.
Lehman sounds just poor with the LCD-3. It has the power to drive them loud, but the sound definitely not of my taste. The highs are ok, but there is neither transparency of O2, no air of tubes. Middles are good, but the biggest drive back to me is the lehmann's bass. It is either anaemic, blurry. I didn't tried the lehmann amp with my Sennheiser HD270, but pairing with the LCD-3 is just poor to my ears.
O2 is an O2, it is very good on low volume levels, where it has some spare power headroom, but with the volume turned up it shows the lack of the "drive". The main difference between the O2 and EHHA is representation of high registers. Both amps are shines, but EHHA is on the "pleasant " side, while O2 is on the "neutal - correct" side.
I got an R.N.Marsh amp kits, now I waiting for the PSU modules. It will be interesting to listen, and to add that amp to comparison.
Well, the EHHA rev A kits from glass jar audio are assembled and tested.
First of all, there was mentioned, that EHHA has not enough **** and vinegar to drive LCD-3...
Creative ZX @ 0dB (4.3 V amplitude) 1kHz -> EHHA rev A -> 110 Ohm resestive load-> Tektronix THS720A DSO.
Output voltage amplitude measured so "low" as 38V
. 4.3V is a maximum for my soundcard, so now I unable to find when the EHHA clipping begins. Simple calculation for output power available for an LCD-3 is :P=U^2/R -> (38/2)^2/110 = 3.28W
The recommended amp for an LCD-3 is 1-4W capable. And yes, in "subjective" tests EHHA drives LCD-3 to the ear splitting levels without signs of an overload.
The kits from Glass Jar audio - there is no place for complains. All parts and PCB's are excellent quality. Assembly of EHHA is very simple, the setup procedure - set heater voltages to 6.3V, than set trim pots on amp board to middle position, apply power, check output zero, than set the current of an output devises, let the amp to heat up, finally adjust the current. Amp is ready for Rock'n'Roll
The EHHA runs hot at class A, so enclosure with the good ventilation should be considered.Now how it sounds. In the two words - JUST GREAT. Everything is here: deep and tight bass, clear, airy terrible, beautiful middle. There is not heavy "tubey" coloration, sound is neutral, very involving, with the little, gentle touch of tube's signature. The sound is very clear, good detailed. Due to impressive output power, there is no problems with the dynamics. I can to listen to my EHHA - LCD setup an hours without any sign of fatigue. The noise floor is very low for the tube containing amp. Of course it's not an O2, but the hiss is on the threshold of audibility in very quiet environment only.
I'm happy with that setup. Of course I'll try another amps, but I think it will be hard to beat outstanding performance of the EHHA.
Now the some comparisons. I have O2 modified to use LME49990 at gain stage, and Lehmann Cube clone.
Lehman sounds just poor with the LCD-3. It has the power to drive them loud, but the sound definitely not of my taste. The highs are ok, but there is neither transparency of O2, no air of tubes. Middles are good, but the biggest drive back to me is the lehmann's bass. It is either anaemic, blurry. I didn't tried the lehmann amp with my Sennheiser HD270, but pairing with the LCD-3 is just poor to my ears.
O2 is an O2, it is very good on low volume levels, where it has some spare power headroom, but with the volume turned up it shows the lack of the "drive". The main difference between the O2 and EHHA is representation of high registers. Both amps are shines, but EHHA is on the "pleasant " side, while O2 is on the "neutal - correct" side.
I got an R.N.Marsh amp kits, now I waiting for the PSU modules. It will be interesting to listen, and to add that amp to comparison.
Erm... the EHHA runs on +/-30 V rails, right? That's like what, 57 Vpp tops? That would be 20 Vrms. Plenty high enough in any case, but still. I guess you may have Vpp and Vrms confused.
Not entirely sure how you're arriving at 4.2 V for the ZX either. Specified full-scale voltage for Z and ZX is 2 Vrms, or 5.6 Vpp. But getting to that can admittedly be a bit difficult, especially when output is in shared mode. On Vista that always gave me 3 dB less than exclusive mode or kernel streaming. The rest was level control problems - check the mixer section of the SB control software for relative channel levels. On my Audigy FX those have a tendency of going out of sync when switching back and forth between speaker and headphone operation, and the position of the main volume slider always corresponds to the channel with the highest volume.
Not entirely sure how you're arriving at 4.2 V for the ZX either. Specified full-scale voltage for Z and ZX is 2 Vrms, or 5.6 Vpp. But getting to that can admittedly be a bit difficult, especially when output is in shared mode. On Vista that always gave me 3 dB less than exclusive mode or kernel streaming. The rest was level control problems - check the mixer section of the SB control software for relative channel levels. On my Audigy FX those have a tendency of going out of sync when switching back and forth between speaker and headphone operation, and the position of the main volume slider always corresponds to the channel with the highest volume.
I don't see neither RMS no PK-PK termins in my post, but there is:
Then same measurement taken at EHHA output, loaded with 110 Ohm 4 W resistor. The volume pot set to maximum.
The RMS power output here is 1.73W - still in margins of recommended power output of an amp, to properly drive LCD-3 (and probably 99.99% of the other headphones available)
I added a noise plot if the someone is interesting.
I'm waiting for the upcoming audio analyser https://www.quantasylum.com/content/Home/tabid/40/EntryId/33/QA405.aspx , so in the future I'll be able to share more facts about the EHHA and the oher things.
While my DSO allows the hard copy output, you can to see the output of Creative ZX below.
Then same measurement taken at EHHA output, loaded with 110 Ohm 4 W resistor. The volume pot set to maximum.
The RMS power output here is 1.73W - still in margins of recommended power output of an amp, to properly drive LCD-3 (and probably 99.99% of the other headphones available)
I added a noise plot if the someone is interesting.
I'm waiting for the upcoming audio analyser https://www.quantasylum.com/content/Home/tabid/40/EntryId/33/QA405.aspx , so in the future I'll be able to share more facts about the EHHA and the oher things.
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Just finished R N Marsh amp. It assembly and setup are quite straight forward.
The output voltage drift is about -+5mV - within absolutely safe margins. Amplifier powered from +-19VAC 30W R-core transformer, then LT3015 + LT1963A boards, adjusted to 16VDC output.
First tests were performed with the DDS generator and 100MHz 500MS/s oscilloscope. I did not tested that amp with the load yet, but the first results looks very good : 200KHz signal ( sine, square, triangle, saw tooth) do not contain neither glitches or artefacts. The heat dissipation of the amp is not to big, amp works perfectly with the 150X60X25 heat sink - 43.5C @ 26C room temperature.
The listening.
The setup : PC ->Yulong DA8 mk II DSD DAC -> Van Damme Silver Series Session Grade low cap interconnects -> R N Marsh amp -> Audeze LCD-3F, Sennheiser HD-270 headphones with stock cables.
JRiver player adjusted to DSD output, all DSP - off.
That amp sounds more similar to the EHHA amp - very tight bass, beautiful midrange, refined highs. It is difficult to describe the highs: those very detailed, and airy, probably more detailed than on the EHHA amp, absolutely neither cold or aggressive, but very pleasant. It is possible to spend an hours listening that amp, without the signs of fatigue.
The dynamics is an excellent, neither detail of the music not rolled off, hidden or blurred. Sound is very clean and transparent.
The bass is similar to the bass of the EHHA amp - powerful, tight, and VERY DEEP. This is the best bass and heights I heard from the solid state headphone amp.
The only a thing that Marsh amp clearly lost to EHHA amp is the ability to drive LCD-3 to the ear splitting volume levels, while maintaining the timbre balance. EHHA is clean winner here due to 2 times higher supply voltage, lower value of source resistors and much higher output power as result. But that fact not making Marsh amp "outclassed" from usage with planar magnetics headphones - it plays loud, clean and pleasant.
So final of comparison with my favourite hybrid amp : EHHA - more on the warm, tube side, while still not "tubey" coloured or distorted, Marsh - more on the neutral, analytical, solid state side, while still very pleasant and relaxed.
Marsh amp shines with the sensitive Sennheiser HD270 phones. There was no winner here to me. Power hungry Audeze LCD-3: EHHA's power is unbeatable, but at the volume levels below those like on the rock festivals - Marsh is the equal competitor to an advanced tube-SS hybrid amp.
The Lehman Linear clone, OPA2134, manually matched transistors and Dale resistors - looses to the Marsh amp in terms of bass quality on both - Sennheiser and Audeze. The highs of the Lehman are OK, but less airy to my taste. March amp is faster, and more involving.
O2 amp - modified to use LME49990 opamp, Dale resistors, 5KOhm Brouns volume pot.
O2 is very neutral amp. It doing excellent job with sensitive headphones. It`s colder than Marsh amp. There is nothing to much to complain about it, but from all of the amps above it has smallest output power. Within certain volume levels, it can be a good competitor to any amp, but to my taste Marsh is better. It just more pleasant to my ears.
While both: O2 and Marsh amps are ultra low THD+N, the one can tell, that my opinion is biased, because the distortions of both amps are quite below threshold level of sensitivity of human's ear, and both should to sound the same. Well, I did not performed blind ABX testing, and my current opinion is still as above - I prefer Marsh amp.
The several worlds about tech-diy com Marsh amplifier kit. All parts are $54 + $3 for the PCB. Resistors are Dale RN, power caps are Panasonic FC. Matched transistors packed in the separate bags. Green PCB with white, very well done silkscreen. Kit coming with printed assembly manual - simple and informative. So there is nothing to complain, or to improve about quality.
The parts not included in kit but still required to build an amp: fine quality volume pot, some good voltage regulator, mines transformer, input and output sockets, heatsink.
My though - do not save coins on parts and components for that amp, because while completed, that amp will pay you with the probably best sound that solid state technology can to deliver.
The output voltage drift is about -+5mV - within absolutely safe margins. Amplifier powered from +-19VAC 30W R-core transformer, then LT3015 + LT1963A boards, adjusted to 16VDC output.
First tests were performed with the DDS generator and 100MHz 500MS/s oscilloscope. I did not tested that amp with the load yet, but the first results looks very good : 200KHz signal ( sine, square, triangle, saw tooth) do not contain neither glitches or artefacts. The heat dissipation of the amp is not to big, amp works perfectly with the 150X60X25 heat sink - 43.5C @ 26C room temperature.
The listening.
The setup : PC ->Yulong DA8 mk II DSD DAC -> Van Damme Silver Series Session Grade low cap interconnects -> R N Marsh amp -> Audeze LCD-3F, Sennheiser HD-270 headphones with stock cables.
JRiver player adjusted to DSD output, all DSP - off.
That amp sounds more similar to the EHHA amp - very tight bass, beautiful midrange, refined highs. It is difficult to describe the highs: those very detailed, and airy, probably more detailed than on the EHHA amp, absolutely neither cold or aggressive, but very pleasant. It is possible to spend an hours listening that amp, without the signs of fatigue.
The dynamics is an excellent, neither detail of the music not rolled off, hidden or blurred. Sound is very clean and transparent.
The bass is similar to the bass of the EHHA amp - powerful, tight, and VERY DEEP. This is the best bass and heights I heard from the solid state headphone amp.
The only a thing that Marsh amp clearly lost to EHHA amp is the ability to drive LCD-3 to the ear splitting volume levels, while maintaining the timbre balance. EHHA is clean winner here due to 2 times higher supply voltage, lower value of source resistors and much higher output power as result. But that fact not making Marsh amp "outclassed" from usage with planar magnetics headphones - it plays loud, clean and pleasant.
So final of comparison with my favourite hybrid amp : EHHA - more on the warm, tube side, while still not "tubey" coloured or distorted, Marsh - more on the neutral, analytical, solid state side, while still very pleasant and relaxed.
Marsh amp shines with the sensitive Sennheiser HD270 phones. There was no winner here to me. Power hungry Audeze LCD-3: EHHA's power is unbeatable, but at the volume levels below those like on the rock festivals - Marsh is the equal competitor to an advanced tube-SS hybrid amp.
The Lehman Linear clone, OPA2134, manually matched transistors and Dale resistors - looses to the Marsh amp in terms of bass quality on both - Sennheiser and Audeze. The highs of the Lehman are OK, but less airy to my taste. March amp is faster, and more involving.
O2 amp - modified to use LME49990 opamp, Dale resistors, 5KOhm Brouns volume pot.
O2 is very neutral amp. It doing excellent job with sensitive headphones. It`s colder than Marsh amp. There is nothing to much to complain about it, but from all of the amps above it has smallest output power. Within certain volume levels, it can be a good competitor to any amp, but to my taste Marsh is better. It just more pleasant to my ears.
While both: O2 and Marsh amps are ultra low THD+N, the one can tell, that my opinion is biased, because the distortions of both amps are quite below threshold level of sensitivity of human's ear, and both should to sound the same. Well, I did not performed blind ABX testing, and my current opinion is still as above - I prefer Marsh amp.
The several worlds about tech-diy com Marsh amplifier kit. All parts are $54 + $3 for the PCB. Resistors are Dale RN, power caps are Panasonic FC. Matched transistors packed in the separate bags. Green PCB with white, very well done silkscreen. Kit coming with printed assembly manual - simple and informative. So there is nothing to complain, or to improve about quality.
The parts not included in kit but still required to build an amp: fine quality volume pot, some good voltage regulator, mines transformer, input and output sockets, heatsink.
My though - do not save coins on parts and components for that amp, because while completed, that amp will pay you with the probably best sound that solid state technology can to deliver.
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