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Review of Little-Dot MKIVse - Page 10

post #136 of 833
Thread Starter 
Quote:
Originally Posted by Caribou679 View Post
Hi!

I have been following these reviews about the different LD MK tubes amp with alot of interest. They are great!

My main question is this: I use a Sony MDR7509HD headphone with 24 ohms of impedance. I read the requirements with these amps are 32 to 300 ohms. What would happen if I use my headphone with them. Can I dammage the amp or the headphone?

Also what would happen if the driver tube was inverted( by error?) with the power tube?

regards,
Hi! I'm really not sure about the headphone situation, but your best bet is to go to little-tube.com and send a MSG to DavidZ and ask him directly about your headphones. He will know for sure if anything special needs to be done.
On the tube question, the driver tubes are smaller and can't fit the larger sockets of the power tubes. Good thing too, or I might have done this myself!
post #137 of 833
Quote:
Originally Posted by Caribou679 View Post
Hi!

I have been following these reviews about the different LD MK tubes amp with alot of interest. They are great!

My main question is this: I use a Sony MDR7509HD headphone with 24 ohms of impedance. I read the requirements with these amps are 32 to 300 ohms. What would happen if I use my headphone with them. Can I dammage the amp or the headphone?

Also what would happen if the driver tube was inverted( by error?) with the power tube?

regards,
The lower impedance shouldn't hurt the amp, I think the specs were listed like that because all Grados are 32 ohms and most Sennheisers are 300 ohms, so it's just convenient to choose those two points for reference. Theoretically speaking, TOO low of an impedance will drain more current from the amp than it can provide and cause it to clip, but I think the LD amps are plenty powerful enough that it shouldn't be a problem, besides, tube amps clip nicely.

About inverting the tubes, it's impossible. On the Mk-series, all the driver tubes are 7-pin and the power tubes are 9-pin as well as having incompatible sockets. The power tube and driver tubes look different too, so you won't confuse them. The main thing to worry about is making sure the internal jumpers are set to take the right kind of driver tubes (EF95 or EF92 or EF91), I don't know what would happen if the jumpers were set to the wrong type of driver tubes, so that's worth asking David about.

- DoA
post #138 of 833
I only have few hours on my unit and I noticed that mids are a bit sucked-away right now. Singer comes much closer when I switch to my SACD-player's own hp jack. Guess I'll have to connect my MKIV SE to computer and let it play songs all night long.
post #139 of 833
Thread Starter 
Quote:
Originally Posted by Seba View Post
I only have few hours on my unit and I noticed that mids are a bit sucked-away right now. Singer comes much closer when I switch to my SACD-player's own hp jack. Guess I'll have to connect my MKIV SE to computer and let it play songs all night long.
Yep, you got it. There are some huge caps in that amp, and it takes time to heat form them, so run it, run it, run it. Somewhere around 65-85 big changes happen and can go on as far as 125-140. Hang in there! Glad it arrived!!
post #140 of 833
Thread Starter 
Quote:
Originally Posted by Dept_of_Alchemy View Post
The lower impedance shouldn't hurt the amp, I think the specs were listed like that because all Grados are 32 ohms and most Sennheisers are 300 ohms, so it's just convenient to choose those two points for reference. Theoretically speaking, TOO low of an impedance will drain more current from the amp than it can provide and cause it to clip, but I think the LD amps are plenty powerful enough that it shouldn't be a problem, besides, tube amps clip nicely.

About inverting the tubes, it's impossible. On the Mk-series, all the driver tubes are 7-pin and the power tubes are 9-pin as well as having incompatible sockets. The power tube and driver tubes look different too, so you won't confuse them. The main thing to worry about is making sure the internal jumpers are set to take the right kind of driver tubes (EF95 or EF92 or EF91), I don't know what would happen if the jumpers were set to the wrong type of driver tubes, so that's worth asking David about.

- DoA
When I first got my MKIVse, I purchased a matched set of RCA 5654's and put them in the amp (mine takes only 408A's) and turned it on. Those little RCA's were like mini flashlights!!! I turned it off and took them out after cooling, but it was funny! 6volt vs 20volt I think.
post #141 of 833
Well, it's been over 2 weeks since I last purchased my Little Dot MKIV SE. David finally shipped it out last Friday, and when I track it on USPS, this message appears: "Origin Post is Preparing Shipment". I'm not sure what that means but I sure hope it means it's on it's way here. Anyone know what it could mean? I searched around the web but found no answer.
post #142 of 833
Does anyone knows the difference in SQ between 5654 and WE403A in LD MKIV?
post #143 of 833
Quote:
Originally Posted by YZHI View Post
Does anyone knows the difference in SQ between 5654 and WE403A in LD MKIV?
The 5654 is the generic US tube, it can sound fine depending on the manufacturer. 403A was made by Western Electric with the 403B being an improved version and the B version was much better and subsequently adopted by other manufacturers. In my experience the 403B sounds more accurate and more dynamic than the stock 5654's.
post #144 of 833
Thread Starter 
Quote:
Originally Posted by Xoen View Post
Well, it's been over 2 weeks since I last purchased my Little Dot MKIV SE. David finally shipped it out last Friday, and when I track it on USPS, this message appears: "Origin Post is Preparing Shipment". I'm not sure what that means but I sure hope it means it's on it's way here. Anyone know what it could mean? I searched around the web but found no answer.
Not sure, but it sounds like they are about to hand it over to USPS. Did you try the tracking at EMS? It will tell you more, same tracking number.
post #145 of 833
I let my amp burn in for 10hrs last night playing "Dark Side of the Moon" SACD on repeat.

Mids are coming up but maybe not enough still. Highs are cleaned up nicely.
post #146 of 833
@Seba
what is the gain of your amp?
but from my experience MKIV did not made the mids on RS2 fuller
post #147 of 833
Quote:
Originally Posted by Bozz_Keren View Post
@Seba
what is the gain of your amp?
but from my experience MKIV did not made the mids on RS2 fuller
Default gain, I think it is the lowest. I'm still burning it in. All I can say that I've never heard so much detail from music before. So MKIV SE is a definate upgrade to my previous amps.
post #148 of 833
in my previous setup was MKIV -> RS2
IMO, the setup is not to my liking, MKIV have better synergy with HD650, but your taste maybe different from mine
post #149 of 833
Quote:
Originally Posted by Bozz_Keren View Post
in my previous setup was MKIV -> RS2
IMO, the setup is not to my liking, MKIV have better synergy with HD650, but your taste maybe different from mine
What made you not to like RS-2's with MKIV (do you have the SE or non-SE?)
post #150 of 833
non SE, hmm, the mids kind of lean, and the bass doesn't extend too low, the amp made the sound smooth but lean,
later i discovered HD650 and been happy since then
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