[jude]

After reading about the PreHead, and after a chat with Kelly via AIM earlier, I'm interested, for the first time since acquiring a Max, in possibly acquiring another amp for my personal reference rig.

To my ears, the Max is a phenomenal piece of head-fi gear, and I'm actually very happy with it in my rig right now. But, like so many other audio enthusiasts, other gear does tempt me from time to time. Since acquiring the Max, not too many headphone amps have truly tempted me, because, thanks to HeadRoom, I'm now an admitted crossfeed addict, and not too many headphone amps out there come with crossfeed (and certainly few of the Max's calibre).

So for the first time in ages, I'm considering picking up another amp for my personal reference rig -- the PreHead. It has the crossfeed. It has four inputs. It looks versatile. Early impressions of Kelly's hint that it has the fidelity. He did mention to me that, among other things, it has very solid bass performance. Given that the Max is near-standard-setting in this regard, this is good news to me. Spoiled by the Max, I've found several headphone amps lacking solid bass extension and drive, and this is very important to me.

Kelly forwarded me an e-mail from Jan with the specs and photos (which I believe have been posted here before):[size=xx-small]

1. 4 inputs
2. Passive bypass output on input 4
3. 1 preamp output (maximum gain factor 2,4)
4. 2 headphone outputs (0 Ohm / 120 Ohm output impedance)
5. Maximum output voltage 15 V
6. Maximum output current 800 mA
7. Gain switch with two settings: low / high (maximum gain factor 2,4 / 10,2)
8. Variable crossfeed filter: headphone OFF / stereo / low / medium / high
9. Sturdy aluminium enclosure (8 mm frontplate)
10. Laser engravings
11. Weight: 2425 g
12. Size: 22 x 22,5 x 8,4 cm
13. 110V and 220V versions available
14. Gold-plated inputjacks
15. Silver plated headphone jack (Neutrik)
16. Silver and gold plated heavy duty switches (Lorlin and C&K)
17. Alps Potentiometer
18. 25-watt toroidal transformer (Talema)
19. Built-in mainsfilter (Schaffner)
20. Built-in groundloop breaker
21. Schottky rectifying diodes
22. Low impedance electrolytic capacitors (Panasonic). Total buffer capacity 44.000 uF
23. Polyester bypass capacitors in the powersupply
24. Polystyrol and polypropylen (Vishay) capacitors in the signal path
25. Metalfilm resistors
26. Double sided PCB with 70 um copper
27. LM6171 opamps biased into class-A using LM334 current sources
28. BUF634 buffer amplifiers (3 per channel)
29. double regulated voltage lines
30. Star-grounding
31. Very short signal paths
32. Signal paths at the bottom side of the PCB for shielding
33. Option 1: AD8610 opamps instead of LM6171
34. Option 2: 5 inputs and no passive bypass

[/size]Unlike Kelly, and based only on what I've read, I'd probably opt for the AD8610 option over the standard LM6171 opamps, as I do prefer detailed, but also smooth, sonic presentation. I'll wait for Kelly, and maybe one or two other PreHead customers, to comment on their experiences with this product before I decide. But I'm feeling good that there's finally another higher-end headphone amp out there with crossfeed for me to at least seriously consider.

I'd also consider buying a Gilmore amp if crossfeed was an available option. When it is (I'm merely guessing it will be some day), I'll probably have to pick one of those up, too (or instead). We'll see. A lot going on with headphone amps lately, eh?

 

[HappymaN]

jude, a bit off-topic, but I just saw a picture of you on the HeadRoom website...

...all this time, I thought that was you in your avatar...

 

[jude]

[size=xx-small] Quote:

Originally posted by HappymaN jude, a bit off-topic, but I just saw a picture of you on the HeadRoom website... ...all this time, I thought that was you in your avatar...

[/size]It actually is me in the avatar. They wouldn't allow me into Ireland with my trademark arrow.

If you haven't been around Head-Fi for that long, you probably haven't seen any other photos of me. I know, from photo to photo, I can look a little different.

Click here for a more detailed view of my avatar.

Click here for a reverse angle body shot.

Okay, now back on topic....

 

[Nick Dangerous]

Agreed. The Gilmore and Prehead-1 are high on my "must demo" list...

 

[kelly]

Quote:

Originally posted by Nick Dangerous Agreed. The Gilmore and Prehead-1 are high on my "must demo" list...

Working on it.

As you guys probably already know, it takes me a little time to become acclimated to a new audio component and this is why I don't tend to post first impressions. I don't want to mislead people with what is just as likely me momentarily overpriortizing the one thing the component does right or conversely condemning a component based on something else. Granted, there are times when I think "ew yuck" and I'm pretty much done with a component forever in the first five minutes, but this is pretty infrequent in high end stuff.

After I get past the nuevo experience, I'll then try multiple headphones on it and hopefully a couple of sources to try to further isolate the amp's signature. Then finally I'll do some AB comparisons with some discs I'm very familliar with and write a horribly misspelled and grammatically incorrect bunch of dribble that is hopefully somewhat descriptive and useful. That's the goal, anyway.

So, grain of salt if you hear anything from me before the end of the month.

It's ironic that Jude posted those pics and specs. Jan of course didn't post them here due to the advertising policy. Jan had emailed a couple of people who were either involved or had expressed interest privately and then of course, I had a dozen or so people interested enough that I forwarded the email. We really have to figure out some way to get new product information posted without robbing Head-Fi of advertising revenue. Users wanting to see this information is part of what drives traffic to the site, so it's kindof a catch 22.

 

[Gergor]

Very appealing amp, I wish I had hold off buying the headmaster. Price and function wise is a direct competition of the Sugden preamp. It'd be interesting to see how they compare in sound...

 

[kelly]

Quote:

Originally posted by Gergor Very appealing amp, I wish I had hold off buying the headmaster. Price and function wise is a direct competition of the Sugden preamp. It'd be interesting to see how they compare in sound...

The Corda Prehead is missing a certain something that the Sugden has... what is it.... how do you say it? I'll have to think about it. HMMM. HMMMMMMMMMM.

 

[DarkWolf]

What is the expected cost of this unit? It looks cool!

 

[kelly]

Quote:

Originally posted by DarkWolf What is the expected cost of this unit? It looks cool!

It's $775 and is not offered as a kit.

 

[Gergor]

Quote:

Originally posted by kelly The Corda Prehead is missing a certain something that the Sugden has... what is it.... how do you say it? I'll have to think about it. HMMM. HMMMMMMMMMM.

kelly, you're killing me!!!!

 

[Jan Meier]

Dear Headfellows,

"pics and specs. Jan of course didn't post them here due to the advertising policy."

It's just part of the story. The pics aren't shown on my home-page also. I simply hadn't time to do the changes. I decided to make a first series of amps first to have some stock. This showed to be quite a time-consuming process. It takes around 5 hours to fully build and test one single amp! I hope to add detailed pictures tomorrow.

"The Corda Prehead is missing a certain something that the Sugden has... what is it.... how do you say it?
I'll have to think about it. HMMM. HMMMMMMMMMM."

HUMMptie dumptie sat on a tree??

Cheers,

Jan

 

[jude]

Okay, I've had some private e-mails with Jan, and he suggests the LM6171 opamp instead of the AD8610. Can someone with experience (DIY'ers perhaps?) with both, please express some opinons on the matter? I'm not for a clinical sound. I'm not saying that the PreHead has a clinical sonic presentation with the LM6171's (remember, I've never heard it), but LM6171's do have more of a reputation for that than, say, the AD8610's.

Again, I'd very sincerely appreciate some opinions on these choices.

Here's a question specifically for anyone who happens to already own one of these PreHeads (read: kelly): how are the RCA jacks? I don't need fancy shmancy, but I do need durable. Do they look/feel like they'll last through a lot of cable changes with aplomb?

 

[kelly]

The jacks are solidly built and I trust Jan's soldering a lot more than the average guy so I wouldn't worry about that. They're not as "nice" as the Cardas found on the Max and Corda Blue which are like $30/pair or something ridiculous like that and honestly I question the value of such exotic jacks on commercial amps. The ones he uses strike me as the $3 or $4 variety as opposed to the 50 cent variety but I'm sure there are better people to assess that than me.

This is obviously one of the ways Jan establishes a lower price point than competitiors. You'd also notice that he doesn't use a rear anondized plate like the Max has.

 

[Wodgy]

Jude, I haven't heard the LM6171, but from Jan's description it seems like it corresponds fairly closely to the sound of the OPA637. This is a classic solid state sound; very detailed but not terribly liquid. The AD8610 is much closer to the sound of a fine tube amp; detailed but vocals are wonderfully smooth and realistic. In my opinion the AD8610 is just much more musical. I was really surprised by this; after all, the OPA637B (highest grade) costs about $44 for a stereo pair, while the AD8610B (highest grade) costs only $16 for a stereo pair.

The LM6171 is probably more of an unknown quantity around here than the AD8610. I don't think you'd go wrong by choosing the AD8610; it sounds splendid. (I guess the LM6171 could possibly sound more splendid

... someone will have to A/B them.)

 

[kelly]

Some day when Jan gets production up and Dallas has another meeting, maybe I can talk Jan into sending an 8610 one.

I would read with a bit of skepticism any comments from anyone who hasn't heard the LM6171 with the LM current sources. By the same token, the OPA637 biased with FETs isn't really the same thing as an OPA637 alone.