[Flea Bag]

Greetings!

I had three weeks with the Prehead MkI before sending it back, actually due to a fault of my own. Very nice of Jan to allow me to do so. Well, I replaced it with the MkII version

and it arrived just this morning.

It's now 2350hrs here in Perth so I haven't had much time with it but here are some initial impressions:

1. What surprised me was how much brighter the MkI was, despite last hearing it well over a month ago. The MkII has better balance and gives me the impression that it is more forgiving. However, it may also have slightly less air. I'll have to look deeper into this.

2. The amp sounds very stable, powerful and with good instrument separation.

Stable is the word I choose to use because instruments seem to stay very well separated and don't seem to loose their presence when others come to join the party. Depending on the recording, I can close my eyes and visualise the position of the various instruments and effects around me and then pick whichever one I want to listen to. Only on very noisy passages or perhaps due to bad recordings and my so-so DAC do these instruments get 'drowned out'.

3. However, I confess there is a down-side. One that I seemed to have got used to in just a few hours... When I first hear the amp in the morning, I don't think I was used to hearing such severe instrument separation. This resulted in quite a lot of fatigue and I was falling asleep! I did after a few more minutes!

Well I woke up about an hour later and that 'fatigue' issue hasn't repeated itself since.

The other downside which I also quickly got used to was how the amp initially sounded 'empty' but spankingly clean. I think it's due again to the extreme. instrument separation. I've got used to this too.

So, there's nothing left to do but enjoy the music!

 

[Slow_aetk]

Welcome to the Prehead MkII team.

You'll need to go well over 100 hours burn-in before the Prehead MKII develops its magic. At the beginning I found it limited in both the bass and treble extension. This will slowly disappear and you'll get the full "bandwidth". Also, detail will increase and the soundstage will develop and open up.

This amp is very detailed, with an airy and precise soundstage. With some very good binaural recording (Aachen Head) I have, with sax and organ in a church, you swear you are in there!
You'll get full and very natural treble, medium and bass, plenty of dynamics.

The only downside, is that I found the extreme bass "punch" a bit shy compared to Kurt's Dynamight

 

[Flea Bag]

Quote:

Originally Posted by Slow_aetk Welcome to the Prehead MkII team. You'll need to go well over 100 hours burn-in before the Prehead MKII develops its magic. At the beginning I found it limited in both the bass and treble extension. This will slowly disappear and you'll get the full "bandwidth". Also, detail will increase and the soundstage will develop and open up. This amp is very detailed, with an airy and precise soundstage. With some very good binaural recording (Aachen Head) I have, with sax and organ in a church, you swear you are in there! You'll get full and very natural treble, medium and bass, plenty of dynamics. The only downside, is that I found the extreme bass "punch" a bit shy compared to Kurt's Dynamight

Hmm... I'm quite okay with the bass as it is but if it gets any deeper, I wouldn't mind! However, I admit that treble could get a bit sharper. I remember how unforgiving the MkI was with some of my recordings but the MkII seems just a bit too smooth and forgiving with the same tracks. I really need that sharpness and air to kick in!

Yeah I had a similar binaural experience with a live performance of Concrete Blonde singing 'Mercedes Benz' and woah... it was just like I was there. I could hear her voice so clearly coming from concert speakers! I hope to get that atmosphere to return soon!

 

[Flea Bag]

Just another point to add:

At lower volume levels, the MkII seems to have a more bassy and fuller sound compared to the MkI. I believe this is due the the lower gain of the MkII. Most of you might know that at low volume levels, quite a number of solid-state amp can sound thin and lacking in bass.

I do most of my listening at low volume levels and perhaps this would explain why differences between the two Preheads are so significant. I've talked to Jan about the differences and he confirmed that sonic differences between the two are not supposed to be significant enough to tell apart from long-term memory, only in direct A/B testing.

I'll post more when I'm certain the amp is well burned-in.

 

[Ross]

Flea Bag, I'll be very interested to hear how your Prehead Mk II runs in. I have the Mk I and it is a superb headphone amp, and clearly beats the various others I own or have owned (Headroom Maxed Home (old version), Linsley Hood Chiarra, Naim Headline/Hicap, WAD HD83, SR-71, Earmax Pro, and a few others). I have been tempted to buy the Prehead Mk II with stepped attenuators, but am having difficulty justifying it, especially as one or two reports have suggested that the MK II is brighter than the Mk I, which is obviously not what you are experiencing.

 

[cpw]

Have you been using the crossfeed?
CPW

 

[Flea Bag]

Quote:

Originally Posted by Ross Flea Bag, I'll be very interested to hear how your Prehead Mk II runs in. I have the Mk I and it is a superb headphone amp, and clearly beats the various others I own or have owned (Headroom Maxed Home (old version), Linsley Hood Chiarra, Naim Headline/Hicap, WAD HD83, SR-71, Earmax Pro, and a few others). I have been tempted to buy the Prehead Mk II with stepped attenuators, but am having difficulty justifying it, especially as one or two reports have suggested that the MK II is brighter than the Mk I, which is obviously not what you are experiencing.

Yup! It's definitely not bright compared to the MkI(at low volumes). I remember the MkI to be quite bright already before burn-in. Once again, I'm quite sure they sound the same at the louder volume levels, just not the same at lower volumes.

I actually returned the MkI because I couldn't power (via pre-amp outs) a subwoofer without activating the high crossfeed circuitry. Jan offered that I return the Prehead to have the pre-outs permanently activated regardless of crossfeed setting but in the end, I choose the MkII for the pre-outs on/off switch and the tone controls for convenience although I have a good equiliser.

If you listen at louder volume levels, I'm quite sure the MkII will sound very very similar to yours. Have you tried asking anders about his impressions on the MkII SE? I remember him saying that differences were very small but that the SE was more balanced while the MkI had more emphasis on treble.

 

[Flea Bag]

Quote:

Originally Posted by cpw Have you been using the crossfeed? CPW

Nope, not yet. I'm burning in the amp with all settings off/neutral.

 

[Anders]

You should have the crossfeed and filters set on during unattended burn-in, because they are switched off otherwise and then the components in the filters don't burn-in until you use them.
Impressions to come soon!

 

[Flea Bag]

Quote:

Originally Posted by Anders You should have the crossfeed and filters set on during unattended burn-in, because they are switched off otherwise and then the components in the filters don't burn-in until you use them. Impressions to come soon!

I was thinking of burning in the other circuits some other time. That's what I did with the MkI. I rarely use the crossfeed anyway.

By the way, did your impressions on the MkII change much with burn-in?

 

[Flea Bag]

Oh silly me... I'll just wait for your posts. Take your time!

 

[Anders]

I have both Prehead MkI and MkII SE and have got some months of experience now. It is difficult to say how much of the differences in listening impressions depend on Mk I contra MkII because the SE also has a stepped attenuator and higher quality capacitors.
Basically, both versions are well designed and neutral amplifiers with power to drive almost all headphones independent of impedance and sensitivity. It has worked well with all headphones I have tried and I don't perceive it as specially designed for Sennheiser as sometimes has been stated (Jan Meier at least previously had a preference for Beyerdynamic DT931, which indeed is a bright headphone).

I have used Preheads at two locations and with different components and cables and my experience it that it is somewhat sensitive to system matching, but not more so than other amplifiers. It seems advisable to avoid cables that are bright and sharp in character and Prehead also sounds better with power cables with a warm and smooth character (even with a headphone as HD650).

Prehead Mk II SE is a clear step up in my experience. MK I is detailed but Mk II SE has even finer detail and this works favourably as it comes in combination with a smoother and somewhat more flowing sound. Mk II also has better defined deep bass but I don't think there is any difference in dynamics in general, maybe except some enhancement in micro-dynamics in Mk II. However, Mk I has a slightly warmer tonal character which makes them rather similar regarding the overall warmness/coolness dimension. Mk II is less edgy and smoother with enhanced detail and more neutral overall.
I would say that both amplifiers also deviate slightly from a neutral presentation (Mk I more so) with a solid state character that is a little thin with a slightly lacking smoothness and color of tones (this somewhat boring character is sometimes mistakenly called neutrality). For example EarMax Pro has less of this problem and a more natural rendering of instruments, although it has more limitations than Prehead overall. I think this is the downside of the Prehead sound, but it is still a very good amplifier although not perfect.

It is always impossible to say if an upgrade from Mk I is worth the money. Mk II SE is better but there can be other weaknesses in a system that are more urgent (e.g. a good source). , I am satisfied with my own upgrade.

 

[Flea Bag]

Well, there you go Ross. Thanks for the impressions, Anders!

It's still too early for me to post impressions. Will probably do so next week.

 

[Ted-Thai]

My Prehead MKII SE has arrived yesterday, any suggestion on quick burnning-in. At this point, I find lower bass is not what expected and treble is a bit too harsh, however over all is very detail, transparency and certainly will give perfect sound, after the burn-in. I pair it with G08 and HD650.

 

[Flea Bag]

My apologies Ted-Thai,

I've forgot about this thread. I'm too late on suggesting to how to burn-in your amp so how's it going now, one month on?

Your initial impressions on the Prehead MkII SE seem to be similar to how I found the Prehead MkI. Burn-in didn't seem to make the bass much better from what I remember. Perhaps something along my audio chain or the MkI itself was not functioning at 100%.

I say this because the MkII sounded much more balanced right from the first listen while people have been saying that the sonic differences between the MkII and MkI shouldn't be large enough to tell apart from memory, only in a very careful side-by-side comparison. This led me to believe that my MkI wasn't quite functioning properly. I traded it in for a MkII so I didn't have them together for a direct comparison.

I remember another Head-Fier saying that he tested a Prehead at a meet and found it to sound a bit wierd with all the equipment he tried. He concluded that perhaps that particular example was 'sick'.