[johnjen]

hahahahahahahaahahahahahahahahahaha
And wouldn't that be a hoot if they were as 'unusual' as those in your picture…
And they certainly would get the 'novel idea of the year award' hahahaha…

But no they aren't QUITE that 'out there', but they do remind me of the 'Big Blobbs stuck on our head' form factor (audeze, abyss, immediately come to mind).
But heh, I don't have to look at them when I'm listening to music, so they are 'invisible' to me… hahahahahaahahaha

And for an added bit of intrigue, you can see thru them, as in I can see my fingers wiggling on the other side of the driver.
Now doesn't that just frost yer cake??????
Hahahahahahahahahahahahahahhaha

JJ

 

[bcowen]

And for an added bit of intrigue, you can see thru them, as in I can see my fingers wiggling on the other side of the driver.
Now doesn't that just frost yer cake??????
Hahahahahahahahahahahahahahhaha

JJ

I bet they're the most transparent sounding cans you've yet heard?

Ugh....sorry.

 

[johnjen]

Yeah, and I can see INTO the music as it's recreated this way too!
hahahahahhaha

JJ

 

[johnjen]

So the cat is outta da bag.
These mystery HP's are HEDDphones from Germany.
https://www.hedd.audio/en/

And they compare rather favorably to my 800 J-mods but still need more time for my head and their HEDD to get synch'd.

JJ

 

[johnjen]

So these HEDD's are smoothing out and settling in rather nicely as they accumulate hrs, and I'm starting to draw conclusions in terms of differences and similarities to my Jmods.
But they need more time and at the same time I'm reminding myself that both HP's need at least 15-20minutes of playing time BEFORE I begin making comparisons.
To that end I am using 2 amps (The ROK and the 6L6GC) at the same time to swap back and forth between amps and HP's in all 4 combinations.
This way they both stay 'warmed up' and I don't have to wait for them to 'open up' and so I can play the same track twice (or more) back to back…

And I still have an upcoming skype call with the HEDD dudes, to get the inside scoop, straight from the manufacturer…
After that call I'll know what steps I can take next.

JJ

 

[johnjen]

So the Purp-Amp is fully modded at stage 3, and is up and running.
It took a while to get it biased properly and still needs a bit more tweaking, but it's 'in the ball park'.
It has ≈15hrs on it thus far and is still morphing a bit as it settles into it's new configuration.

That being, it's now a direct coupled, CCS (Constant Current Source) controlled for all tubes, DHT (Directly Heated Triode) output tube, HP amp.
It only has 5 component parts in the 'direct' audio path (not counting ground return connections) per channel.
2 tubes, 2 xfmrs, 1 stepped (fixed resistor) volume control, as in, there are no caps in the 'direct' audio path.

It is accumulating hrs in preparation for the upcoming headfi meet this Saturday.

And so far it continues to surprise me with a SQ that has powerful deeply extended bass, along with a detailed and delicate top end, but it's the midrange that 'delivers the goods' in terms of the 'Magic in the Mids' (MitM) as only tubes can.

Nothing sticks out nor seems to be missing in terms of FR and harmonic richness, indeed these MitM acoustic traits are brought to the fore.
And yes it has attained 0.000mvac output (-120dB) s/n for both channels and should stay this way henceforth.

And when I use the HEDDphones on this amp, they respond even more like my 800-Jmods, which tells me they can scale really well.

More later, as things get further dialed in and settle down.

JJ

 

[johnjen]

So I went back 'under the hood' and re-measured all of the parameters and adjusted the bias settings for the Purp-Amp.
They were fairly far off.
So after re-tweaking them, I'm listening to the amp and it has taken a decided step up.
I'll dive back into it and tweak all of the settings again here in a little bit.
I'll keep doing this until they fully stabilize and settle down on their optimized settings, which might take several iterations if this amp follows a familiar pattern of getting used to a particular set of operating parameters.

I also have a 'surprise' single tube/ch amp that I'm also fussing with, which I'll take to the meet tomorrow as well.
It too needs some fussing just to see what it is fully capable of delivering.
This amp is designated the CAA (Cheap Ass Amp) for a reason, as the total parts cost is ≈$150.

More later.
JJ

 

[bcowen]

This amp is designated the CAA (Cheap Ass Amp) for a reason, as the total parts cost is ≈$150.

Hmmm....must be a GE tube. And if so, you should consider designating it just the AA. LOL!!

 

[Tjj226 Angel]

Hmmm....must be a GE tube. And if so, you should consider designating it just the AA. LOL!!

Nope. Russian 6E5P tubes strapped in triode.

Also, GE tubes are great. They aren't super high end, but if I had a budget to build something, I would MUCH rather buy cheap GE tubes and a higher end output transformer or output capacitors than a high end tube and cheap output components.

 

[johnjen]

So Purp-Amp and CAAmp update…

I've been checking and adjusting the bias current on the 71A output tubes about once per day and the range of adjustment has narrowed considerably since the 1st initial bias 'event'.
I say event because it took us a bit of time to dial it in and it wasn't all that close, but the subsequent adjustments have been requiring less adjustment and take less and less time to 'finish' (until the next adjustment) and will continue until both channels fully stabilize and match each other, well at least enough so that further adjustments are no longer needed.

SQ wise there are additional subtle cues and nuances along with inner definition and focus everywhere.
Every once in a while I'll hear a whole new 'voice' or at least that voice won't be buried in the background anymore.

An as I mentioned previously The Who's Eminence Front on their It's Hard album has a bass line that once heard lends a whole nuther level of texture to that song.
It was all to easily missed as it only plays for short bit in that track.
But once heard and it becomes a point of auditory focus, well it is a marvelous voice all unto itself.
And it has opened up and blossomed as these changes further help to reveal nuances in multiple ways, much to my delight.

But wait there's more…
I have a one tube wonder amp here that just got tweaked enough to be worth pursuing in terms of tweaking it any further.
It uses a Russian 6E5P tetrode (strapped in triode for those who understand what that implies and means) using 70v line xfmrs as output xfmrs and jfets for providing a constant current source (CCS).
We were surprised by the results and I aim to push it just a bit to dial in the output impedance to make a better match and perhaps throw some bypass caps at the existing parafeed caps, ya know just because I can… hahahahaha

It's already good enough to want to make it a meet amp.
And we figure it's got about $150 in parts so it makes no sense in going full tweako on it, but it does perform WAY above what it's parts cost would suggest and small 'cheap' upgrades-R-us so pushing this amp won't sting ANYwhere as bad as our other projects.

JJ

 

[johnjen]

So I added yet moar 'secret sauce' to the Purp-Amp, call it v.2.
It's taken a while before the changes have become apparent.
And I need to make another check and adjust session, just because as well.

So after all that, the SQ has begun to blossom and in unexpected ways.
The very top end of the mids where the much saught after tinkle tinkle lives, has stepped up to the bar and is aligned with the deep bass…
Translated this means even the zizz on top has an impact when it's struck or rung etc.
Like when a cymbal is struck there is the whack and the zizz.
This synchronization extends up from the bass, and now down from the top, meeting in the mids.

And I also just cleaned the tube pins, and that may have had something to do with these results as well.

Either way I'll take whatever I can get…
Like the punch of power that a piano can impart when it gets percussively struck.

JJ

 

[johnjen]

So I remember when Led Zep II was released and I had the vinyl album and repeatedly played this album.
It was distorted enough so I could only sometimes understand the lyrics and much of the 'added' distortion just obscured everything else.

The Purp-Amp with these latest Secret Sauce additions and circuit refinements have made it so I can clearly hear the distortion as just guitar amp, or mic-preamp overload on the drums etc for exactly what they are and the rest of the soundstage is not buried in the grunge.

And there is yet one more refinement/mod to the circuitry that I'm figur'n should be the icing on the cake, the one where it all goes "CLICK".
That's my story and I'm sticking with it, well, until I find out after the circuit has settled back down whether or not this is da bomb or just a mere pop.
hahahahahahaha.

But this next mod has a deggree of refinement that is elegant and simplifies the operational flow of the amp, which should yield SQ to die 4.

But I am struggling to take my own advice and leave well enough alone, at least for a while and enjoy the music instead of slinging hot solder.
'Cause damn tunes are really captivating right now.

It's S/S (Spooky/Scary) time, again.

JJ

 

[Tjj226 Angel]

So I remember when Led Zep II was released and I had the vinyl album and repeatedly played this album.
It was distorted enough so I could only sometimes understand the lyrics and much of the 'added' distortion just obscured everything else.

The Purp-Amp with these latest Secret Sauce additions and circuit refinements have made it so I can clearly hear the distortion as just guitar amp, or mic-preamp overload on the drums etc for exactly what they are and the rest of the soundstage is not buried in the grunge.

And there is yet one more refinement/mod to the circuitry that I'm figur'n should be the icing on the cake, the one where it all goes "CLICK".
That's my story and I'm sticking with it, well, until I find out after the circuit has settled back down whether or not this is da bomb or just a mere pop.
hahahahahahaha.

But this next mod has a deggree of refinement that is elegant and simplifies the operational flow of the amp, which should yield SQ to die 4.

But I am struggling to take my own advice and leave well enough alone, at least for a while and enjoy the music instead of slinging hot solder.
'Cause damn tunes are really captivating right now.

It's S/S (Spooky/Scary) time, again.

JJ

Try Led Zeppelin 3 "That's The Way"

At least 1 song on every album they do is something more than a love song.

Also try Rush, The Doors, and Pink Floyd.

Rush will ideally loose the weird overly generic sound signature.

The vocals with The Doors will become WAY more interesting.

And Pink Floyd is well.......Pink Floyd.

Also try some old R&B. That can get REAL interesting REAL quick. A good starting point would be Rubber Band Man.

 

[johnjen]

I'm listening to That's The Way right now and its much like the 2nd album WRT that ability to cleanly an clearly peer into the music.
And I'll add some rush and the doors to boot.
But right now OVERWERK's anthology to Daft Punk is kick'n with gusto.

JJ

 

[bcowen]

I'm listening to That's The Way right now and its much like the 2nd album WRT that ability to cleanly an clearly peer into the music.
And I'll add some rush and the doors to boot.
But right now OVERWERK's anthology to Daft Punk is kick'n with gusto.

JJ

You mean this? Johnjen, I had no idea...