[alanbeeb]

Ok - thanks for the offer to help - I'll get back shortly with what I find.  I'm using highest gain setting +20db

 

[alanbeeb]

Quote:

 
Let's see if it's possible to resolve some of these issues. Find out which opamp is in your LC. What gain setting are you using?
 
 

Hi,  highest gain setting. The opamp appears to have been scraped or rubbed to remove markings - but I can see 45EXY on it. Here is a photo.
 

 
any recommendations? thanks.
 

 

[francisdemarte]

 
Maybe someone else can chime in but I've never seen that opamp before. The fact that the makers markings are rubbed off also makes it suspect. I'd try picking up one of the ones suggested in this thread (lots of discussion in the first 10-15 pages) or the M-Stage thread from a trusted source.
 
I think the one in the original Lehmann was the OPA2134. Here in the States this opamp runs about $3. A lot of people like the more expensive darker bassier OPA627. 
 
Post up the type of music you like to listen to and hopefully other will also jump in with suggestions.
 
In the meantime, you might also want to try playing with the gain settings a little to see if you get any improvements. Some opamps like a certain min/max level of gain to work at their best. 

 

[alanbeeb]

Mainly classical orchestral and heavy rock for me.
 
I have insignificant soldering skills. OK on a big wire but couldn't solder one of these things.... where can I get the opamp already mounted on an adapter? Thanks

 

[francisdemarte]

I'm not familiar with electronic vendors over in the UK. You might try RS.
 
OPA2134PA in 8 pin PDIP format; which is drop in, no soldering:
 
http://uk.rs-online.com/web/p/op-amp/2858069/
 
If you want to try some other drop in replacements:
 
http://uk.rs-online.com/web/c/semiconductors/amplifiers-comparators/op-amp/?sort-by=default&sort-order=default&view-type=List&applied-dimensions=4294884083,4294884089,4294883363&lastAttributeSelectedBlock=Supplier%20Package
 
 
Tam's audio sells the a couple of opamps on adapters and with class A mods. You can get more reviews of this from the M-Stage thread:
 
http://tamaudio.com/store/index.php?route=product/product&product_id=82

Personally, I'd try the OPA2134 opamp first, give your self some time to get used to the sound. If you still don't like what you hear then the LC just isn't a good match for you. You can probably resell it for close to what you paid.
 
Good Luck!
 
 
 
 
 
 

 

[Mad Max]

 
Quote:

Hi,  highest gain setting. The opamp appears to have been scraped or rubbed to remove markings - but I can see 45EXY on it. Here is a photo.
 

 
any recommendations? thanks.
 

Let me help you, sir.
 
 

 
 

 
OPA2134.  It's a jellybean, skip it and get a pair of AD797ANZ or OPA602BP and a socketed adapter to go with them.  These will give you more significant overall improvement in sound over most others.  OPA627 is very colored, and some people like it.

 

[alanbeeb]

Ah..... OK, in that case I've got another 2134 arriving tomorrow but also a 627 and 637. Will see how these go before trying more....
 
P.S. Halle Berry Ha Ha - I've just been RickRoll'd! 

  (see vido link in Mad Max's sig)   25 years ago, people were telling me I was Rick Astley's twin brother. However I am a MUCH better dancer.

 

[alanbeeb]

Ok - the new 2134 that arrived today seems much better than the old one, no spitty grainyness that I was suffering before.   Overall its now slightly better listening experience than the headphone socket on my Sony CD..... which is still a disappointment tbh.  Or maybe the headphone out on that Sony is something special - but the real Lehmann BCL I used to own was clearly superior.
 
I've tried the 627 and 637 - are these straight drop-in replacements?  Because I can't get them to work, sound is there but get almost no volume at all with them?  Am I missing a trick somewhere?

 

[francisdemarte]

The OPA627 and 637 are single channel so you'll need two of them on the adapter that Mad Max posted. 

 

[Zsubbo]

What kinds of skills does one need to complete a lovely cube headphone amplifier kit? Is it enough if I can solder and understand basic electronics ?
 
I'd like to get into DIY Headphone amp building, and this would be my first project.

 

[francisdemarte]

The Lovely Cube is semi-DIY. All you need is basic soldering and some knowledge on how to properly wire up a transformer.
 
The board is completely populated, all you have to do is add the RCA inputs/outputs, transformer, and case it. 
 

 

[Zsubbo]

I'd like to populate the board too, so I can get some practise, before building AMBs M^3, wiring the transformer and the rest should be no problem.

 

[francisdemarte]

Check out the kits at glassjaraudio.com. They have complete kits of the AMB amps, saves you the hassle of ordering from AMB,mouser,digikey etc.
The Mini M^3 would make a great first amp project.
 
Ebay has the "Panda" Amp, which is very close to the Lovely Cube, as a complete kit as well:
 
http://www.ebay.com/itm/HIEND-design-panda-headphone-amp-kit-/320743105306?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item4aadc7631a#ht_5817wt_905

 

 

[Zsubbo]

Thanks for the tips, I'm familiar with them, but I choose the lovely cube because it's the one I would really use out of this three, but I was thinking about http://www.ebay.com/itm/Headphone-Amplifier-kit-Diy-Base-Lehmann-AMP-Circuit-/120764992343?pt=LH_DefaultDomain_0&hash=item1c1e278b57 this one, it looks like an inexpensive firs project for practise soldering.

 

[francisdemarte]

Quote:

Thanks for the tips, I'm familiar with them, but I choose the lovely cube because it's the one I would really use out of this three, but I was thinking about http://www.ebay.com/itm/Headphone-Amplifier-kit-Diy-Base-Lehmann-AMP-Circuit-/120764992343?pt=LH_DefaultDomain_0&hash=item1c1e278b57 this one, it looks like an inexpensive firs project for practise soldering.

Looks okay, the components are not as nice as the LC but it's certainly inexpensive. I would definately invest in a better volume pot.