Replacing tubes in a UA 6176

[smutbasket]

Hey Stick -what's shakin'?

Man, there's way more info you could get about everything you asked in one quick search than if I sat here and typed for six days.

In a nutshell, my experience has been that tube rolling is a crap shoot. In a few cases rolling tubes has netted significant benefits for me. In more cases than that I have either found any differences to be negligible or to detract from the original sound quality in some way. By far the most responsive gear to tube swapping I have encountered is guitar amps. For example, with a Marshall 2203 100w head I pretty much know what kind of sounds and changes to expect if I put an RFT or a Mullard or a Sylvania in v1. The differences are pretty noticeable. The least responsive single type of gear for me has been microphone preamplifiers. Compressors, I've had fun rolling tubes in a few of those. I have only a little experience with rolling tubes in microphones. What little I had turned out well.

The online dealers I have dealt with are KCA, Dougs, theTube Store and Eurotubes. All of them were great to deal with and treated me fair and square. All the reputable dealers are well known on this site. I have also found many tubes on my own. Sources have included talkie movie projectors, organs, old guitar amps, strobe tuners, tape decks, and stereos. I have bought several tubes on ebay as well.

If cracking open your gear and swapping tubes is something you enjoy and WANT to do then it can be a lot of fun. It's time consuming and sometimes you might pull a socket or two loose. You might end up saying it was worth it, maybe not. Me, I'm sort of in the middle. If I love a piece of gear I don't mess with it AT ALL unless it breaks. Other stuff I have piddled and tinkered with to some extent. I've enjoyed it

Learn the etching codes. Read all about the old manufacturers and all the ways to identify what you are looking for. This is the only way to really know what is what out there. It will keep you from being ripped off when buying old tubes. Don't be afraid of new tubes. Some of them are great, especially some of the guitar amp power tubes they're making now.

[Stick]

Thanks for the long reply... yeah, I did do some searching, but my question was really specifically about the UA 6176. I'm not a guitar guy, so I won't be messing with guitar amps, and none of my other gear has a tube in it. (I'm pretty sure Eleven doesn't count.) So, I'm wondering if anyone has replaced tubes in a 6176 and felt like it was an upgrade?

[baskervils]

Originally Posted by Stick

Thanks for the long reply... yeah, I did do some searching, but my question was really specifically about the UA 6176. I'm not a guitar guy, so I won't be messing with guitar amps, and none of my other gear has a tube in it. (I'm pretty sure Eleven doesn't count.) So, I'm wondering if anyone has replaced tubes in a 6176 and felt like it was an upgrade?

Replacing tubes is very easy in all of the UA products. I've had to do it with my 610s. You can also call UA and they can tell you what to get. Very nice customer service.

Replacing tubes is like adding / pulling a Lego off of a toy, or plugging in a USB cable. No worries.

If you do a search, look for 6176 modification or tube mod.

[Stick]

Originally Posted by baskervils

Replacing tubes is very easy in all of the UA products. I've had to do it with my 610s. You can also call UA and they can tell you what to get. Very nice customer service.

Good to know... but, were you replacing yours with the stock tubes because they'd died? Or did you put in something different to change the sound?

[retractablezing]

make sure you don't grab the valve from the top, otherwise you risk ripping the socket out of place. put your hand on the base of the socket, and take off the valve by grabbing it more or less at the middle. don't apply all your force to the top of the valve, otherwise you risk going from tone changing fun to shipping it to UA hassle.

edit: goes without saying that you should avoid touching other stuff inside the chassis at all costs, other than the socket and the valve itself, otherwise you risk some serious injuries or worse.

[TelekonStudios]

I have the 6176, and I replaced the stock tubes with NOS Mullards. Although I thought the stock tubes were fine the Mullards made it more of a character pre. It's sounds beautiful now with a distinct character all it's own.

It my go to for electric guitars and my Royer ribbon mic sounds absolutely gorgeous through it!

I do agree with an earlier poster that said NOS tubes can vary in quality and sound. Check with Bowie here on Gearslutz. I've bought several NOS tubes from him (including the Mullards in my 6176) and have been extremely satisfied.

[baskervils]

Originally Posted by Stick

Good to know... but, were you replacing yours with the stock tubes because they'd died? Or did you put in something different to change the sound?

I didn't put fancy tubes in, just high quality ones. I don't have a 6176, just preamps and a LA-610. I noticed a difference because my tubes were crackling and the new ones didn't!

I had a Fender Bandmaster modded about 10 years ago, which is a tube guitar head. That made a huge difference, but the old caps, resistors and tubes were switched. I recently bought a new Fender Champ, but I got rid of the stock tubes and speaker and that helped.

The 6176 is a very high quality piece of gear. It can't hurt to switch the tubes out, but I don't know if you'll notice a massive difference without the guts really being worked on by mod people.

If you think that the sound may not be up to scratch, you can try some new tubes but I wouldn't do any heavy mods. It's a great piece of gear. Tubes aren't too expensive. $20 - $40 each, some are sold in sets.

[dabigfrog]

its good to know how to do. if only to keep tube geAR in service for sessions.
its also good to have a backup set of tubes for all your tube gear, guitar amps, mics...

I had an La2a start farting during a session, it took a week to order & get all the tubes and she was back upp n running pdq... it was the chinese made tube that was the culprit! but I bought it second hand so I don't know if that was the stock tube UA uses... but I did buy 5-10 of each of the tubes so next time I'm only down for minutes not weeks.

the quality vs price of some NOS tubes is always debatable but your ears should tell you whether stock tubes or fancy old rare tubes .... and if you can't tell just go for quality tubes!

[Stick]

Thanks guys. I'll probably keep what I've got for now so I can really learn the unit in it's stock form... but, it's probably a good idea to get another set of tubes for the pre for an "in case" down the road.

[zulusound]

Revamping an old thread... I did find this info from UA:
Microphonics Test for the Universal Audio 6176, 2-610 Grayface, 2-610 Silverface, and M610

Remove the top cover of the unit. Turn on the unit and let it warm up for about 5 minutes or so. Replace the cover lid, but do not install the screws just yet.
Set the Input Select switch to MIC 500 ?, Gain switch to +10, EQ switches flat, EQ toggles to the middle. With no input to the unit, send the output signal from the unit to any channel on a mixer. Set the faders on the mixer to about halfway up. Do not send output to the main monitors. Use headphones only, but do not put on the headphones yet.
Slowly turn the level knob all the way up. If you get a squealing sound before the output reaches full level, that’s a symptom of a bad tube.
If the unit reaches full output as it should, then put on the headphones — but just partially! Remove the cover lid, and with the tip of a fingernail, gently tap on top of the tubes (be careful!). Listen for any pops, spikes, rattling, or noises other than a normal hiss. Any noise present in the audio path is a sign of a bad tube.
If you find a bad tube, replace that tube only. Then, repeat the microphonics testing process to make sure everything works properly. If you get more problem results, test any remaining tubes.
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Replacing Tubes: 6176 Channel Strip

These units require changing one 12AX7/ECC83S tube at location V1 and one 6072/12AT7 tube at location V2.

Although the 12AT7 tube and the 6072 are interchangeable, there is a small variation in the power circuitry that may reveal subtle differences in gain or distortion levels at full gain. We recommend that if your unit was originally equipped with 6072s, you continue to use that tube. Likewise, if your unit is equipped with 12AT7s, it is ideal to continue using that tube.