LampizatOr Generation 4/Level 4... Now we're talking!

ted_b · « **Reply #240 on:** 1 Dec 2013, 09:35 pm »

Gang,these are not difficulties, they are simply an inverted polarity (something that is part of most tubed output stages). As I warned earlier, i think many of you are worried over out-of-phase issues...I'm not talking about that. I'm talking 180 degrees. If a unit inverts phase, and another in the signal path also does, then you back to same phase, that's all.

wisnon · « **Reply #241 on:** 1 Dec 2013, 09:40 pm »

Quote from: ted_b on 1 Dec 2013, 05:19 pm

As some of you are aware I have encountered some incompatibilities with the proto DSD Lampis I've listened to so far. No big deal; they have been rectified. However, since I am on to other eval commitments now during the lull we have come to a decision that we will put off a full eval until after the holidays...when Lukasz builds me a new DSD DAc with what he's learned from my feedback, etc. (Note: again, most of it is purely parochial to my setup, a 2V RMS limitation, etc etc).

With all that being said, I still have one question about the DSD-only DAC I still have here (and am breaking in for the next guy). That question surrounds absolute polarity. My Concert Fidelity pre, like most tubed output stages, inverts polarity (i.e the mfg points out that the simple fix is to swap black/red speaker wire amp leads on both channels). This issue is also prevalent in quite a few tubed analog stages (Modwright mods, etc). Yet I've never heard a Lampi owner talk about it, and I can't seem to get an answer from Lukasz. Do you folks swap your speaker wire amp leads (again, I am NOT talking about out of phase issues that are corrected by fixing ONE channel...those anomalies are mistakes and not a result of tubed output stages)?

Ted he did answer and you forgot (I was on copy). It was only and issue on the DSD only prototype. The reference recording test-tone he used to finalize the Dac was inverted and ths his Dac was also inverted. He did not check it against known recording before finalizing (its a prototype, and so not a big deal). This is not an issue on the PCM Dacs.

ted_b · « **Reply #242 on:** 1 Dec 2013, 10:24 pm »

Norman,
No, that is also not what I am talking about. That was an incorrect channel output (left channel vs right).

Anyway, nevermind. Sounds like even if it is no one hears it. On my pre it is subtle but once heard correctly is noticeable (woofer inhaling when it should be exhaling).

k6davis · « **Reply #243 on:** 1 Dec 2013, 11:45 pm »

ted_b,

I'm not really clear about what it is that you're saying. In part, that's because I lack some of your technical understanding.

Can you explain why you feel that the issue you've encountered wouldn't be a concern for other Lampi owners - and soon to be Lampi owners, such as myself? It's significant enough for you to suspend your review, but you also seem to suggest that it may not have much impact on most people.

I *think* you're saying that your tubed preamp (and most tubed output stages?) invert polarity. Since my forthcoming Lampi DSD with volume control has a tubed preamp output stage, I'm concerned that its polarity will be inverted going directly into my SS amp.

Perhaps I've misunderstood you and this is nothing to be worried about...?

ted_b · « **Reply #244 on:** 2 Dec 2013, 12:14 am »

First off, inverted polarity from a tubed output stage is nothing to be CONCERNED about! At all! It just means you must flip the black and red leads on your amp or speakers (amp end is usually easier cuz it's usually only one red and one black post per channel). It is merely a design consideration. And if it does not exist with the Lampi (i.e does not invert) then so be it!

My concerns about my proto DSD-only DAC from Lampi (I needed 2V rms max output; I had a faulty filter board, I had a faulty USB board etc) has everything to do with the fact that the DAC was an early prototype....and has NOTHING TO DO WITH this invert polarity question. They were two entirely different points in post earlier today. Sorry for any confusion.

dminches · « **Reply #245 on:** 2 Dec 2013, 12:19 am »

Quote from: ted_b on 2 Dec 2013, 12:14 am

First off, inverted polarity from a tubed output stage is nothing to be CONCERNED about! At all! It just means you must flip the black and red leads on your amp or speakers (amp end is usually easier cuz it's usually only one red and one black post per channel). It is merely a design consideration. And if it does not exist with the Lampi (i.e does not invert) then so be it!

But what if the rest of your sources (phono pre, CD player) did not have an inverted polarity? Wouldn't that mean something is compromised?

Big Red Machine · « **Reply #246 on:** 2 Dec 2013, 12:35 am »

My Lampi 4/4 is growing on me and may become as cult a product as my Dude, to me. Those Duelands are broken in and really sing in both the Dude and Lampi. Both great units from two geniuses in the industry.

ted_b · « **Reply #247 on:** 2 Dec 2013, 12:46 am »

Quote from: dminches on 2 Dec 2013, 12:19 am

But what if the rest of your sources (phono pre, CD player) did not have an inverted polarity? Wouldn't that mean something is compromised?

David,
The invert issue is usually with tubed variable output (i.e using the tubed output as a pre). It is assumed it will be the last thing your amp sees. If you are not going direct then I gotta assume there is one less active voltage gain stage (i.e not inverted). So Lampi's with no volume control may likely be non-inverted.

Gang, this stuff is not new. Here is a CJ FAQ about it.
http://www.conradjohnson.com/It_just_sounds_right/cjfaq.html

I just wish we had this kind of info, that's all I'm saying. And it sounds like no one else has asked. I can't really tell at my end because the proto I have is still breaking in, and the output is too high to use with my CF pre correctly anyway. But most designers who have "tube preamp" capability leave the unit in invert mode rather than adding a second potentially noisy voltage gain stage that then inverts again...and with Lukasz's minimalist tendencies I assumed it to be the case with your Lampi's goin' direct. That's all!

wisnon · « **Reply #248 on:** 2 Dec 2013, 12:47 pm »

Quote from: ted_b on 1 Dec 2013, 10:24 pm

Norman,
No, that is also not what I am talking about. That was an incorrect channel output (left channel vs right).

Anyway, nevermind. Sounds like even if it is no one hears it. On my pre it is subtle but once heard correctly is noticeable (woofer inhaling when it should be exhaling).

OK, Understood now...its a slightly different issue. No answer there from me then.

dminches · « **Reply #249 on:** 5 Dec 2013, 12:23 am »

I got my Lampi 4/4.5 with DSD and I am very impressed. This is a wonderful sounding DAC. The mid range detail is unequaled while not being harsh or fatiguing. This bass on Way Out West is the best I have heard from a digital source.

These are very early impressions but I can tell how good this unit will sound in time. And I am still using my SB Touch and not my PC server. That will happen this weekend.

Thanks Lukasz and Fred.

shadowlight · « **Reply #250 on:** 5 Dec 2013, 02:04 am »

Quote from: dminches on 5 Dec 2013, 12:23 am

I got my Lampi 4/4.5 with DSD and I am very impressed. This is a wonderful sounding DAC. The mid range detail is unequaled while not being harsh or fatiguing. This bass on Way Out West is the best I have heard from a digital source.

These are very early impressions but I can tell how good this unit will sound in time. And I am still using my SB Touch and not my PC server. That will happen this weekend.

Thanks Lukasz and Fred.

Congratulation. Looking forward to further impression. Did you get Jensen caps, ecc40 tube with 5Y3 rectifier tube?

k6davis · « **Reply #251 on:** 5 Dec 2013, 02:07 am »

Quote from: dminches on 5 Dec 2013, 12:23 am

I got my Lampi 4/4.5 with DSD and I am very impressed. This is a wonderful sounding DAC. The mid range detail is unequaled while not being harsh or fatiguing. This bass on Way Out West is the best I have heard from a digital source.

These are very early impressions but I can tell how good this unit will sound in time. And I am still using my SB Touch and not my PC server. That will happen this weekend.

Thanks Lukasz and Fred.

Congratulations dminches! And these are obviously first impressions, before any benefits from break-in!

I'm waiting for my Lampi to arrive. I can't wait to move from reading about it.. to listening to it!

How did you have yours configured?

Gopher · « **Reply #252 on:** 5 Dec 2013, 02:35 am »

Quote from: dminches on 5 Dec 2013, 12:23 am

I got my Lampi 4/4.5 with DSD and I am very impressed. This is a wonderful sounding DAC. The mid range detail is unequaled while not being harsh or fatiguing. This bass on Way Out West is the best I have heard from a digital source.

These are very early impressions but I can tell how good this unit will sound in time. And I am still using my SB Touch and not my PC server. That will happen this weekend.

Thanks Lukasz and Fred.

You are very welcome!

So glad to see first impressions are so positive. Things will improve significantly with burn in!

dminches · « **Reply #253 on:** 5 Dec 2013, 03:00 am »

My configuration is Ecc40s, 6x5 rectifier and Jensen caps. I don't know what the stock tubes are, maybe Mullard cv3884s. I am using a Tung Sol 6x5 in place of the stock 6x5.

dminches · « **Reply #254 on:** 5 Dec 2013, 01:42 pm »

I have yet to open the case and see what's inside. Does anyone know what the uF is for the caps, and how many are in there?

wisnon · « **Reply #255 on:** 5 Dec 2013, 05:33 pm »

If SE then 2 caps at 0.47uF and circa 600VDC. Double the number for balanced.

I like the ECC40 sound, but I have heard that Tungsram is better than all the other types. Try hunting some down on Ebay, should be $40-60 a pair delivered.

dminches · « **Reply #256 on:** 5 Dec 2013, 06:34 pm »

I did find a couple pair on ebay. There are pretty cheap. In the past 5 years I have accumulated a lot of 6SN7s and ECC32s so in comparison these tubes are really well priced.

Big Red Machine · « **Reply #257 on:** 5 Dec 2013, 07:20 pm »

Quote from: wisnon on 5 Dec 2013, 05:33 pm

If SE then 2 caps at 0.47uF and circa 600VDC. Double the number for balanced.

I like the ECC40 sound, but I have heard that Tungsram is better than all the other types. Try hunting some down on Ebay, should be $40-60 a pair delivered.

Yes, worth it. And the TungSol 6x5.

dminches · « **Reply #258 on:** 6 Dec 2013, 01:06 pm »

Do the ECC40s come with a mark so it is clear how the tube should be inserted into the socket? This tube is part of group of tubes with no guide pin and pins equally spaced.

jriggy · « **Reply #259 on:** 6 Dec 2013, 01:45 pm »

Quote from: dminches on 6 Dec 2013, 01:06 pm

Do the ECC40s come with a mark so it is clear how the tube should be inserted into the socket? This tube is part of group of tubes with no guide pin and pins equally spaced.

There should be a little glass nub that gets lined up with a line/mark that has been put on the socket. The ecc40's I've had have even been marked on (in red), incase the nub is to hard to see or cant be felt during insertion.