Hi all,

Wanted to talk a bit about tube upgrades to the Universal Audio LA-610. I am by no means an expert on tubes (or “scientific” clip comparisons), but as I know that there’s been a good number of threads on the subject, and I don’t recall ever hearing any clips, I thought I’d take a crack.

Just over a year ago I was somewhat disenchanted with my LA610, so I thought I’d look into upgrades. I was in contact with Christian Whitmore (fellow GS member) from Pro Audio Tubes, and he made some fantastic recommendations, and presented me with a ton of options.

I pulled the trigger on the following replacements tubes, and FINALLY (yes, they sat in a box for a year), I took the time last night to do a quick before and after recording.

TUBES USED:
Input stages:
-NOS Telefunken 12AX7
-NOS Mullard 12AX7
Other stages:
-The 6AQ5, new, cheap US-made piece*
-Side chain: Vintage 12AX7*
-Output tube:* NOS GE 6072

Note, there are 2 “after” recordings, as Christian suggested I play with swapping the V2 and V3 input gain tubes for different tones (Mullard > Telefunken or Telefunken > Mullard). I was surprised at the tonal impact that had!

Anyway; there is nothing done to these tracks; it’s me playing and singing into a Flea 47. Identical settings on the LA-610 in all cases.

I am interested to hear which tone people prefer, as I actually think they’re all pretty good (aside from the fret/string noise…but that’s my mediocre playing and mic placement)…but I did have a favorite in the end.

LA-610 Stock tubes: https://www.dropbox.com/s/fqa0nz0afm...stock.wav?dl=0
LA-610 Mullard > Telefunken: https://www.dropbox.com/s/7ex3jfi0lx...-tele.wav?dl=0
LA-610 Telefunken > Mullard: https://www.dropbox.com/s/p0h48eyndf...llard.wav?dl=0

The NOS tubes were not super cheap (as that’s where the market has pushed them). I think I spent $300 on the lot? Anyway — I am pretty pleased with the configuration, and look forward to getting to know the LA610 a bit more. I think the overall quality is improved, and I will be promoting the pre’s use in the future!

I will “reveal” my preferred combo in the future if anyone cares; but for now, I just hope this is of interest for some people / help contextualize what sort of changes to expect with some tube rolling in the unit.

Cheers!

Yeah I dealt with Christian in the past and can vouch for him as well. yes tubes to make a difference in these sort of units. I liked the mullard > tele most then again the mic position could have changed and some clips are louder than others to my ear. But even with some quick quicktime level adjustments I felt that mullard > tele had the nicest balance and tightness of the signal. Both tube changes gave a nice compression to the sound which made it seem more glueish the original was more sloppy but then again maybe your tubes were old? OR maybe the mic position changed a lot? The dynamics overall seem different.

Thanks for responding. Always nice to hear from people after you do clips.

Acknowledging mic placement could impact things, I found that Mullard then Telefunken to be best too.

Christian framed the sound of the tubes as the teles having lots of highs and mullards as being super smooth.

When the teles were first, I thought the highs got a bit stiff.

Hello BObO

Thanks for sharing your experience with the 610 tube mod.
Please if you can upload it again because the files are deleted

Thanks
Alban

Hey there!

I blew away my Dropbox a while back, but fortunately made some backups.

Hopefully this link works, and you can browse as you like...

https://www.dropbox.com/sh/v12a7vf49...5a1_XsnAa?dl=0

Thank you very much.

I
I just heard them, and amazed because the difference was as if you had bought another device.
Maybe I'm wrong but for me, the best was the combination `Mullard-Tele`
Maybe because I'm a bit of a fan of clean, airy sound.But anyway something looks more natural and beautiful to this combination


I would like to ask you if you have made any other changes with the other tube,
because I read an article where the last tube is changed which is Output compressor and at the same time a resistor is set, which reduces the distortion of the compressor output, for this reason I do not work the compressor at all, because I do not like the sound that comes out of it even if the compressor does not work at all.


And another new question if you can, tell me about the other tubes as an example
-The 6AQ5, new, cheap US-made piece *
-Side chain: Vintage 12AX7 *
-Output tube: * NOS GE 6072
Where did you buy them or what brands are exactly, because I am new to the tubes business, and when I google search there are 1000 types of tubes?because I'm afraid that if this combination is not as identical as you did, then this sound will not come out the same.

Anyway, I really liked this combination you made and I will do the same
And I want to thank you very much

Cordially Alban

Glad this was helpful!

I did NOT make any other changes.

Per the original post; I bought the tubes from another user here on GS. I'd suggest you look him up and see if he can hook you up.