Antique Sound Labs OTL32

[Nefarion]

I am seriously considering selling my recently aquired ASL MG/OTL MG head in an attempt to upgrade to the OTL32...

My reasoning behind this upgrade are (from what ive heard):

A. Overal sound inprovement with the 580/600's over the MG/oTL.

B. Matches better with low impendance cans

C. Remote Control option


I am planning on getting some grado RS1's down the road... And i was hoping not to have to put out for another home amp for those (already have a portable from fixup). Which I know i will have to do with the mg/otl. But i do not want to make the switch from the mg/otl to the OTL32 if it does not improve on the sound of the hd600's. For that is my "main rig".

I already decided if i do sell my ASL MG/OTL head it will be as a package with the upgraded tubes and all the tubes i bought for it... It only 2 weeks old.. Less than 30 hours on it (i LUUUUV it btw). Raytheon 5751 in the middle.. 2 JJ EL-34's on the outsides.. Plus 2 extra JJ's and the stock tubes. A total value of $360 (exactly what i payed for everything without shipping) that i will sell firmly for $280 if i decide to do so. Then i will have to start saving for the OTL32!

I guess what im trying to confirm by this post is that A,B, and C are true.

I would also like to know when this is expected to be available at divergent.

I would also like to confirm that the price will be approximately $500 w/0 remote $600 with.

 

[mcgino]

As one of the few OTL32 owners, I have to say that the OTL32 sounds better to me than the OTL with HP-1s. I drove AKG K1000s for a while with them and they sounded really great (if only the K1000s fit my head better). I am listening to an MG-Head OTL at home (with R10s, F1s, and sometimes AKG240DF for kicks - waiting for the new Twinheads to be manufactured) and I like the sound of the OTL32 more. Especially with the Telefunken 12au7 tubes I put in. You might want to save your tubes as the OTL32 uses the same tubes (just need two 12au7 and four 6bq5s).

Not sure about the pricing or remote (mine is a prototype and didn't have a remote).

 

[Orpheus]

didn't joe say that the otl32 is specifically for low impedance cans?--that would mean it's inappropriate for the hd600? i thought the "32" was the value of the optimum impedance (grado's have impedances of 32ohms) is this right?

 

[wasifazim]

Quote:

Originally posted by Orpheus didn't joe say that the otl32 is specifically for low impedance cans?--that would mean it's inappropriate for the hd600? i thought the "32" was the value of the optimum impedance (grado's have impedances of 32ohms) is this right?

No, the OTL32 is capable of driving both low- and high-impedance 'cans, as opposed to the DT/OTL which are only satisfactory with high-impedance phones. The Head OTL32 is ASL's mid-range headamp..according to Tash Goka at Divergent, the OTL32 will retail for about Cdn$900 (US$600 or so)..

- Wasif

 

[Nefarion]

So is it safe to say the 580/600's will sound better with the otl32 than with the mg otl? This is a big factor for me... IF the upgrades for the otl32 only involve making it low impedance satisfactory, while not improving or even decreasing the quality of high impedance performance.. Its not something i want.

mcgino - So, from what you have heard, the otl32 drives both high and low impedance headphones better than the mg/otl?? The only factor im really concerned about in my decision is long as it can drive the high impedance cans...As the "rumor" been going around is that its only meant for low impedance. Also, Can you clarify for me exactly what tubes the otl32 uses...And how many? Thanks a bunch


Also - This unit will for sure be available, correct? Any idea on when (weeks,months?).. Its not just some "concept" that might be in the market right? I want to be sure before i even think about selling my current amp.

 

[wasifazim]

Quote:

Originally posted by Nefarion Also - This unit will for sure be available, correct? Any idea on when (weeks,months?).. Its not just some "concept" that might be in the market right? I want to be sure before i even think about selling my current amp.

Again, according to Tash, the OTL32's ETA is three weeks..

- Wasif.

 

[Nefarion]

Thats good to hear. Thats right around when i will be ready to buy...Thanks for the info

 

[Orpheus]

"No, the OTL32 is capable of driving both low- and high-impedance 'cans, as opposed to the DT/OTL which are only satisfactory with high-impedance phones. The Head OTL32 is ASL's mid-range headamp..according to Tash Goka at Divergent, the OTL32 will retail for about Cdn$900 (US$600 or so).."

...here is a quote by Joe Lau about the OTL32 in another thread:

"It will be a real OTL Headphone amps to drive 32 Ohm Cans."

so, yes, the "32" designation IS about the load of the headphones it will power...

nefarion in another thread:

"I too an interested in these answers. From what ive been told (from multiple sources) .. The new 32 version is designed for low inpedance cans (not hd600) and it expected to hit the street within the next month or so. This is only stuff ive "heard". I would like to find out for sure..."

mcgino:

"Joe Lau brought this amp for our recent Hong Kong meet and let us "hold on" to it for a while. The amp is about 1 1/2 x the size of the MG Head, but is an entirely new design that uses four 6BQ5s and two 12AU7 tubes. Joe says that the amp is designed for low-impedence headphones (down to 32 ohms). "

now.... it seems that during auditioning, it was found to work fine with high impedance headphones.... but the fact is, joe originally designed this for low impedance headphones, correct???

 

[Joe Lau]

I'm sorry ! I may be Misleading on OTL32. I design it can drive low impedance Cans but it really great at high impedance Cans.

It just like you water tape in your home. It can supply big flow of water but you need only a little. Just adjust it to lower !

So OTL32 have a high/Low switch. It is only a very simple idea. Low impedance cans need lower output impedance but need lower voltage to drive. So I parallel a low impedance resistor on it but high impedance cans need high voltage to drive and I put a little higher resistor on it !

ALso If you few Low impedance output position damp your cans too much. Just switch to high position even you use low impedance Cans.


I had try other tube in simuliar theory and seem to be so good. I like to share the idea here :

I had also try 6DJ8 connect in SRPP just like 6BQ5. It only need 1 tube /channel. It seem to be still can drive low impedance cans in good condition.

I had also connect 6DJ8 in White cathode follower but it only can drive 150 or high impedance.

So I had a conclusion : SRPP even output impedance not as low as White cathode but it can supplier much more current . So It can drive low impedance cans even better. Due to White cathode follower has a Loading resistor on the top. It limited the current. May be can replace it with a Current sorce will solve the problem.

Oh ! don't forget to parallel a Low value resistor on output. It will lower the output impedance and higher the damping.

 

[Nefarion]

Thanks so much for clearing that up for us Joe!

I think I have decided to upgrade due to the otl32's more "universal" abilities. If I win an amp im bidding on at ebay I will sell my MG/OTL (which ive already had some inquiries about), if not i will keep it as a secondary.