[pigmode]

That TwinHead is a strange piece of equipment. It's listed as a preamp, but it uses 2A3 tubes most often seen driving SET power amps.

 

[Hirsch]

Now that's an interesting preamp. It would be interesting to compare that to the ZOTL and SHA-1 (and perhaps the incoming Moretto, if it's up to the other two). Although, looking at the variety of tubes, NOS could get expensive...

 

[Joe Lau]

Quote:

Originally posted by pigmode That TwinHead is a strange piece of equipment. It's listed as a preamp, but it uses 2A3 tubes most often seen driving SET power amps.

Yes ! It is a Direct Heat Tube use in small Power amps but We design it work on 20 - 25ma only. It will have Ultra long tube life. Why I Choice it ?

1. It have low Plate Resistance.
2. It is a Direct Heat tube - It sound warmer than Indirect Heaat type.
3. It is still in production with many manufacturer in China and Russian... NOS is still avaialble.
4. How many Watt/mW output ? It is depend on your Loading.
It can be up to 1W if you load it with a 8 Ohm speakers. So It can drive a small speakers.

It is a Pre-amps or a Line Amps ? How to classifier it as a Pre-amps or Headphone Amps :

Headphone amps : Gain around 2 to 5 times
Can Drive Impedance down to 24 Ohm to
around 600 Ohm.
Single Input.
Volumn Control.
Low distortion.

Pre-amps : Gain around 3 to 10 Times (Even no gain is acceptable in Passive design).
Can drive medium impedance.
Multi Input.
Volumn Control.

All element need by a Pre-amps except multi input is same as a Headphone amps. I just add more Input RCA and Selector and 2 set of RCA output. It become a Pre-amps. It addition not much in cost but user will benifite on it ! Our Original is design an dedicate Headphone amps but found all Headphone amps can use as a Pre-amps if the gain in right range as Pre-amps. So I Add a Pre-amps function on it !
Do you think a 2A3 is too much power on a Headphone amps or Pre-amps ? I even found some manufacturer use 300B on Pre-amps. It actually not easy to design it ! It is hard to control Hum. Even our prototype show in CES2002 (T.H.E SHow) still get few Hum. We take 2 more weeks to redesign the power supply and it have very low Hum and noise now.
Is it can drive 40 OHm ? Sure It can drive down to 24 Ohm in OTL mode , can down to 8 Ohm in Transformers mode.
What MG-Head OTL can do ? It do better ?
More beep bass , more sweet mid range, better seperation.

 

[Nick Dangerous]

Edwin, it is extremely generous of you to offer to loan me your R10's. The little voice in my head is going crazy and shouting, "GET THOSE PHONES NO MATTER WHAT! HURRY!" but I'm not going to give in to immediate gratification. Instead, let me exercise my patience and propose an alternative: Let's perform all reviews of the LH-01 and TWIN HEAD at the next Head-Fi meeting.

The advantages are significant:

1) More people = more perspectives. More perspectives = greater accuracy.

The Dallas Head-Fi membership is getting very savvy. Many of us have heard a wide range of equipment and own many different amps and headphones. If the LH-01 and TWIN HEAD were present at the next Head-Fi meeting, there would be many more people available to contribute their findings. Also, the number of different headphones and amps present would make for an excellent pool of equipment to test them with. 20 reviews are always better than one.

2) The Oris 200 Project will allow us to give the preamplifier functions an excellent workout.

The Oris 200 Project incorporates highly sensitive Lowther PM2A drivers that will reveal everything and anything upstream in the audio path. What better way to test the preamp functions than this?

The Oris 200 Project is almost complete. Only the construction and testing of the Paraglow 2A3 monoblocks remain. I will be receiving these in early May... meaning that everything should be ready by the end of the month. The middle of June would be the perfect time to hold the meeting and perform the tests.

The meeting should be a blast. Many more people will be present this time around. Lots of Head-Fi'ers, Bottleheads, and newbies will be there... as well as a few out of towners. I'm thinking about 20 people, minimum. Because of the potential crowding, I will not have room to hold the meeting in my apartment.

Solution: Hold the next Head-Fi meeting in a venue such as a hotel conference room or auditorium. We may all need to contribute a little to make this happen.

To sum up:

1) Hold the meeting in a public venue, mid-June.
2) Have everyone bring their equipment as usual.
3) I'll bring the complete Oris 200 system.
4) Have Divergent send Joe's two new headphone amps.
5) Headroom also sends review gear.
6) If I have the MAD Ear 4 completed, I'll also bring it.

Sound good? As far as Edwin's amazingly generous R10 offer goes... I think it goes without saying that everyone here would love to have a listen. However, since these are his personal, private headphones, he may not like the idea of having them used by the entire conference. They may have to wait until after the meeting when I can dedicate a day to reviewing them in my spare time. Edwin, you can PM me with your thoughts on the subject.

Anyone else have any further thoughts?

 

[chych]

Drool!!!!! Time to save up for that twin head

 

[Joe Lau]

Quote:

Originally posted by darkclouds how or what do you hook that reference module up to? I had assume you would have to connect it to a headphone amp but is there one that's powerful enough to drive the K1000 other than the sac.

You should connect to a Power or Integrated amps to get enought power to Drive AKG1000

 

[merc]

Hi Joe!

I have a few questions on the ASL Twin Head Preamp.
How many stereo inputs does it have?
Does it have a unity gain processor loop/bypass?

Thanks!

 

[dhwilkin]

The TwinHead definitely looks interesting. Aside from the 2A3 tubes, does it use the same tube types as the MG Head OTL? What brand of stock tubes (please don't say Sovtek) will it come w/? How susceptible is the unit to EMI/RFI? Will it have a detachable, IEC-style power cord?

Also, doesn't Moth Audio make a 2A3-based headphone amp as well? That might also be an interesting comparison...

 

[merc]

dhwilkin: Based on this image:

It does look like the Twin Head uses some of the same tubes(Sovtek) as the MG Head. I believe that that is a Sovtek EL84 tube on the right?

 

[dhwilkin]

See, I really didn't like the Sovteks in the MG Head DT, way too fuzzy & warm, lack of transparency, etc... If it has twice the number of tubes as the MG Head, tube rolling could be prohibitly expensive. At least let the TwinHead ship w/ something besides Sovteks.

 

[merc]

Quote:

See, I really didn't like the Sovteks in the MG Head DT, way too fuzzy & warm, lack of transparency, etc

dhwilkin: I agree entirely. A relatively inexpensive tube upgrade for me was to use JJ EL84 tubes in place of the Sovteks. Big improvement for little money. If those are 5751s that I see on the Twin Head, they might be NOS Sylvania JAN5751 tubes with the blue printing. If so, they are a slight improvement over the 5751 that shipped with the MG Head OTL.
Then again, I am a rookie, what do I know.

 

[Joe Lau]

Quote:

Originally posted by merc dhwilkin: Based on this image: It does look like the Twin Head uses some of the same tubes(Sovtek) as the MG Head. I believe that that is a Sovtek EL84 tube on the right?

Rectifier Tube NOS
Regulator Tube - EI 6BM8
12AX7 - EI
2A3 - China

Yes ! It have detachable IEC socket.
No EMI Filter but have a Regulated Power supply. It can reject the EMI.

 

[markl]

Can two people listen simultaneously, or only one at a time? That Twin Head is beckoning... must resist...

Somebody buy it and review it pronto!

markl

 

[andrzejpw]

<stands very patiently, not saying much, just waiting for all those MG Head Dt/OTLs that will be soon unloaded in the for sale forums>

 

[2 channel]

Quote:

Originally posted by andrzejpw <stands very patiently, not saying much, just waiting for all those MG Head Dt/OTLs that will be soon unloaded in the for sale forums>

I second that!!! In fact, you guys can just contact me direct and we can both save time!