Mullard E188CC - but with tight bass?

I just digged into tube rolling a bit as my dac (Lab 12 Dac 1 Reference), which is using ECC88s and variants in its output stage, needs a shot of energy and atmosphere.

The stock tubes were 6922 Electro Harmonix. Well, they were okay but nothing special and lacked a precise bass. I changed over to the legendary Amperex bugle boys. My dear, that was an excellent, precise and powerful bass, but the mids were too upfront and I couldn’t relax with them.

Next one was a pair of Siemens E188CC from 1966. Excellent tube, great dynamics, but a bit too cold and lean for my taste and the bass wasn’t as good as from the bugle boys. Finally I now got some RTC E188CC from the early 70ies. Wow, that was the midrange I was missing all the time. Absolutely rich, voluptuous and full of textures. Really amazing, just like the 3D soundstage. The only thing that bothers me is the bass. Again it’s not 100 percent tight and precise enough. Maybe on par with the Siemens but not with Amperex (I have to admit I just used them for 3 days now. Maybe the burn in process will improve the bass but who knows).

So my question is - is there ANY tube out there with such an impressive rich, involving and delicate midrange like the RTC E188CC combined with a tight and precise bass like Amperex? What about the Mullard E188CC - or is it the exact same tube? Valvo, Genalex? Open to anything but I’m not looking out for a compromise regarding the midrange.
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The tightest bass is typically associated with Tele's but you give up some midrange they don't tick all my boxes  You may want to try the Mazda 7308/E188CC from the early 60s.
Digitalviper, I don't think so.. ;] my Abyss 1266 PHI TC already IS a subwoofer and the First Watt F6 dual mono can kick his ass. It's more about fine-tuning. I don't just need a massive bass, it has to be tight!

@tvad Thanks for the link. That's really helpful. What are the exact differences between the mullard you mentioned and the E188cc?

@three easy payments. Yeah that's the trick. Don't want to miss the mullards cozyness in the mids and of course I know this is usually associated with a tubey bass. Is the Mazda as thick and rich as the mullard with a better bass? 
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Ok. That’s what I wanted to hear. Will definitely keep an eye on them. Thanks!

Still open to other solutions of course. 
You didn’t burn your RTC’s in. I’m using the Mullard RTC E188CC (7308’s) and they provide me with everything you’re looking for. Suggested by Brent Jessee, they’ve extended the bass in my system. The 7308 also have a clearer top-end than other Mullards. 
Made in UK for French military. I think the Mullard E88CC/6922 is a great tube as well.

@lowrider57 I thought and hoped so even though the bugle boys didn't show any improvements through a process of around 100 hours of burn in.

In contrast to this the Mullards bass sounded much better yesterday evening. So when do you think can I expect them to be fully "broken in"? 
Telefunken, Mullard and Tungsram. in that order. If you haven't tried Telefunken, you should. Don't cheap out, make sure on the vendor. Tungsram is a true diamond in the rough too.

Mullard is like GE to me they make great valves and they have their name on a lot of so so valves also. Make sure, the older the better for the most part.. 50-70s some of the best ever made. I like the BP and BB Mullard produced.

Marconi is another hit and miss but a great valve too. They just have to be tested.  In a preamp though, they can last a lifetime..

They ALL produce what is there, like a good preamp valve should. I've never used preamp valves to do anything other than get the WHOLE signal to the power amp section, without bass bloat, forward mids or HF boil.

Tellies,  Great RCAs or Mullard in a perfect world.. I've used the same valves for 40+ years.. I know what they do..

Tight BASS.. decouple your speakers all of them.. That would be the first thing I would do. Then 1/2" at a time position your speakers. Closer to the wall for more bass, away from the wall for less. 

I think valve swaps would be the last thing to do..  No tone control either? I do things a little different, I think.. :-)

Barista, I think my Mullard RTC 7308's needed 60 hours of burnin. You should have very good bass extension by then unless something in your system is limiting the low-end.

And the heavy engineer makes a good suggestion to 
tighten up the bass.

I have the Mullard RTC 7308's as well plus the Amperex 7308's...both from the 60's.  They all sound great but the Mullards do have better bass and deeper extension.  Just keep in mind that compared to 6922's the 7308's have slightly lower gain. It has a peak gm of 11,500 micromhos where the 6922's peak at 15,700 micromhos.
I never used a 5687. Where are you using it? In something AN I'll bet.

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Start a new thread here (just for fun)...

Used 5687's to drive 300B's (Audion), but there were DIY preamps popular around that time - 18/20 years ago (based upon a commercial Japanese design - I think) that used them.

You might get some advice, plus list the 5687 unit you are using (didn't see it listed in your system).


Start a new thread here (just for fun)...

@dekay, I came across an old Audiogon 5687 thread. It refreshed my memory of the top contenders...TungSol, Sylvania Gold Brand, Bendix. 

Yes, the Tung-Sols seemed to be favorited (requested) by the DIY preamp crowd as far as I recall, but there were many versions.

The "special" TS's were those with gold/bronze/copper colored plates and/or the same color upright support rods (forget which as I may be confusing some of this with TS 12au7's used in AN and AN knock-offs of the same time period).

I gave away gobs of both to DIY'ers @ the time as I had 2 shoe boxes full of both types (gifts from a tube dealer who was on his last dance with brain cancer).

As a 300B driver my favorite was Sylvania GB (more meat on the bones/harmonically rich), but I also discovered that the non-GB versions with identical construction sounded the same in the Audion amp.

The GB 5687's also included later versions which were sans gold plated pins and which were of different construction (still badged GB).

Apologies for this OT stuff, but I have not responded to the OP due to his entirely different take on 6922 types that I've used and am familiar with in phono and line stage gain positions (chalking it up to different gear/synergy).


As a 300B driver my favorite was Sylvania GB (more meat on the bones/harmonically rich)

That rings my bell. I had a prime pair many years ago and stupidly sold them because I no longer owned the component. Will have to source some more.