Review of Little-Dot MKIVse - Page 51

What gain did you set on your IV SE? x3 or x4?

Where is the best place to buy backup and upgrade tubes for LD IV SE?

Same here. I have to send my LD MK IV SE back.

Do your tubes still glow? But no sound and the amp does not get hot now.

I haven't changed it from 3. Despite what has been said earlier I can't see the point, especially with the Audio Technica's. The maximum volume I use is 10 or sometimes 11 oclock making it unfeasable to raise the setting.

Ebay has a ton of them

Here is a good key word search

(*403A, *403b, 408a, 408b, *415A, 5654*, *5654, 5591, CV4010, CV5216, CV8246, 6069, CV10442, EF95*, M8100, 6AK5*, CV10100, CV8159, CV8225, CV850, 6J1, EF92, 6CQ6, CV2023, V884, VP6, M8161, CV131, 9D6, W77)

This will get you started ... Lots of tubes out there.

Maybe I should start a separate thread about this, I dunno. I recently splurged on a pair of 6H30DRs to replace the EH gold pins that come standard on the Mark IVse. At first, I feared I had wasted my money because the sound was substantially the same, particularly with my AKG701s which are not yet fully broken in. But after about 15 hours of burn-in for the new tubes, things changed dramatically, and particularly with my stock Denon 2000s. I should note that the stock driver tubes were replaced with NOS Voshods right out of the gate when I received my amp more than a month ago. Signal is coming from my Classe CDP.5 thru DH Labs ICs purchased custom from Moon Audio. I was not thrilled at all with the sound of the Denons with the EH 6H30PIs. The bass was bloated and not well controlled and the treble was harsh. With the DRs, the treble is silky smooth and the bass is tight and powerful. Right now I am listening to Andrew Bird's Noble Beast and the sound is rich, organic, and has cohesion that I was not getting with the EH stock tubes. The second track of Drive By Trucker's "The Dirty South" is called "Tornadoes" and opens with a startlingly thunderous set of drum strikes that are both tuneful and powerful, and oh so pleasing with the Denon 2000s. This is great synergy, and most unexpected since the D2000s are thought to need solid state. I was beginning to believe the naysayers of the LD line-up, and was beginning to have doubts about the ultimate sound quality of the Mark IVse. Time will tell as to durability and reliability, but there should be no doubting the potential SQ once source, tubes, and phones choices are matched up. I just hope my 701s eventually flesh out and give as much pleasure as the Denons.

I haven't considered to roll the power tube, because I don't know if the improvement is justified for more than $300/pair expense.

I don't think the difference is likely worth $300. I got a good deal and paid half that for a pair of 6H30DRs. If you have D2000s and are not happy with the sound, you might want to think about finding a pair of DRs at a decent price.

Do they still glow? Once it started smoking, I powered it down and did not power it back on. It's in China with David now. He hasn't said what was wrong with it. Last word from him was an e-mail saying he had reimbursed my return shipping and that my replacement unit was being tested.

If I get any more useful information, I will post it here.

Yes the Tube's still glowed.

I think I got my LD about the same time as you. I think August of 08.

Anyway my LD is on its way back to China.

Don't think there is much to worry about.
David really try's to do things right.

And its because of David I got the LD.

Roger that. David does seem committed to make things right. That said, I would like to know what went wrong with the amp. Don't want a repeat once I'm out of warranty.

So, what caused my Little Dot to smoke out and die?

According to David, "Higher than normal outlet voltage (~130V) caused the heater voltage to oscillate too high, causing eventual failure of the power tubes and burn out of the circuit. The circuit has since been revised to accommodate such conditions."

130V isn't that far outside the normal operating range of a 120V outlet, from what I can tell and I did have my amp and other equipment connected to a home theater-grade surge protector. Whether the protector had been degraded by absorbing multiple surges, I can't rightly say. Nothing else in the chain is exhibiting any problems.

To be on the safe side, I have another surge protector on its way and an electrician coming out to upgrade my outlets from two-prong to grounded three-prongs. This is as much a matter of convenience and safety as real concern about leaking voltage. I'm also considering having a whole house surge suppressor installed.

Any thoughts, advice, similar experiences out there?

I have a PS Audio - Premier Power Conditioner.

Really does a nice job. Holds volts at 121v. Plus It takes noise out of the current among other things.

Do anybody use a tube amp and LD amps in particular with extreme metal/rock. Or is it a no no with tubes.

For $2,000, I should hope so!

But seriously, for the ultimate in clean, steady power, you should consider upgrading to a radioisotope thermoelectric generator, or RTG. Finding plutonium-238, however, can be a pain.