45DRDs in the house

[dubai2000]

Now the following is something I had meant to write for quite a while now, but as I encountered some tube problems (more below) things got delayed.

But start at the beginning: some time in late autumn last year I happened to do some window shopping and saw a pair of ss rectified 45DRD amps with NOS Sylvania power tubes apparently bought at a reputable tube dealer. I contacted the seller (who not only turned out to be an excellent kit builder, but has by now also joined our forum thanks, spaaaz) and we quickly agreed on details. The amps were the basic kit version and I was keen on having the ASC/Black Gate mod done, the latter no longer offered by Ron. Luckily another forum member offered his most generous help (Erik, where would I be without your support?) and soon I received two boxes full of SET amps.

So far things went very smoothly, the following is a bit more puzzling. I recall that when I first used the amps I was struck by their clarity and speed, especially at the low end. But somehow there seemed to be a slight hole in the middle which of course explains why I noticed top end clarity and bass speed straight away. Additionally, the sound was very smooth and inviting.

Forward about a month. Perhaps it was the new caps breaking in or my ears were simply getting used to the amps, but the mids seemed to have filled in nicely, hence this impression of speed got somehow less dominant. What remained was openness which made it very easy to be drawn into the music. Of all the traditional SET amps I have owned, this was/is definitely a keeper.

Having decided on that I parted with a pair of 2A3 tubes and got some EML Mesh plates in exchange. Unfortunately these turned out to be defect but thanks to the sellers persistence (I should say that Ed Sawyer who visits other boards frequently is a great/supportive gentleman!!!) I received a new pair of solid plates. Dropping these into the amps added even more quality. The sound became altogether larger and, if possible, even less speaker bound. In terms of preamp I am happy to report that the DRDs work very nicely with the Transcendent Sound GG, but also, with a different flavour and perhaps to my own surprise, with the MX110 (okay, I have a weak spot for that unit).

Of course that might leave one question: if I had to choose between the 45DRDs and the SE OTL, which would it be?

Well to be honest, I am very happy that I do NOT have to make that choice. Lets put it this way: for me the DRDs main characteristic is their transparency/openness and a feather like touch (which does not mean that they are only good for small scale music at least under my listening circumstances). Their ability to create a believable soundstage is very convincing and their tone is always smooth, but never in a way that something seems to be missing at frequency ends.

The SE OTL on the other hand is remarkably in its natural balance. With it I never feel that any frequency is unduly emphasized. In that sense its very natural and transparent as well. It also gets completely out of the musics way and soundstaging is first rate as well. Do I realize less bass? Definitely not, is the amp slower? Again, no. Still its tone is somewhat different. If the DRD strike you as open and light (in terms of quick), the SE OTL is...balanced again cant seem to find a better word, and quick and musical.

One last observation: both amps are rated similarly, but somehow the SE OTL seems to have a bit more steam. Both, with GG and MX110, I dont seem to have to turn the volume knob to the same degree to get similar loudness. In terms of noise I'd call both amps silence, with the SE OTL having a very slight advantage.

So which is the one to get? Obviously: both but bearing in mind prices (also for those EML which are very costly -IMO), the SE OTL might be the cheaper way to audio bliss. But remember: those listening impressions have been reached in MY room, with MY music, so results might vary in other households.

Wolfram

[Erik Mandaville]

Wolfram:

Another forum member also has 45 DRDs, and absotutely loves them. I have to say that I almost couldn't believe the amount of sound that came out of those things. In all their 1.5 watt (or thereabouts) glory, they sounded enormous in our house. Not only that, the 45 seems to have many of the same qualities of the 2A3 (which is essentially two 45s connected in parallel and installed in a common envelope), but with an even finer and more delicate top end than the 2A3. This was my impression of it, in any case. Compared to it's older sibling the Moondog, the DRD 45s seemed lighter and more quick on their feet sonically. Top that off with amps that are so incredibly quiet for DHTs, and one ends up with a really great product. I knew at the time of purchase, if you don't mind my mentioning this, there was some concern over the SS rectifiers, but to me that just became of such secondary concern compared to the sound that it simply didn't matter.

I was glad to help, and it was great fun working on and listening to them!

Erik

[Erik Mandaville]

Wolfram:

"Perhaps it was the new caps breaking in or my ears were simply getting used to the amps..."

I think you may have touched on a very important possibility with this statement. I have often wondered about the 'break-in' issue, and sometimes think we may in fact be undergoing (possibly more...) more of a break-in period than the component in question!

[Erik Mandaville]

I'm sorry, the SE OTL uses a small amount of feedback, which is not a good thing.

[Daddy Dee]

Wolfram,

Thanks for your take on the 45's. Interestingly enough, I've been thinking that I need to make a choice between the Wright 2A3's and SE OTL for WAF. Well, everytime I switch from the Wrights to the SE OTL, I think, DANG, I can't get rid that! It's just too good.

[Erik Mandaville]

...and, I love my Moondog amps and will never part with them. They are in our main listening room, and we still hook them up and enjoy them on a regular basis.

[dubai2000]

Yes, I am glad the choice between ss or tube rectified was taken off my shoulders . Erik knows how often I debated that within myself because I had been contemplating those amps (albeit in their 2A3 guise) even before getting the SE OTL.

I should add that built quality of the DRDs is really excellent, something I was not prepared for, but wouldn't complain about either .

Wolfram

[MarkF]

I have both a pair of Moondogs with the ultimate upgrade and RCA Singleplate 2A3's and a pair of ss DRD 45's. IMO they are both very close in sound except the Moondogs have a better lower register but the 45's sound more delicate in the upper mids and treble.

I am in the process of getting a pair of Electro Voice t-350's tweeters re diaphragmed by Electro Voice service center in Arkansas. I had them re diaphragmed by an authorized service center in Minneapolis and both voice coils rubbed and severely limited the frequency response. Apparently it is very difficult to align the diaphragms in T-350's. Once they are properly installed, I am hopeful they will add a significant difference to the 6k - 15kcps range. I expect to have to use an L-pad.

For the mids I am using Altec 288-16K drivers and 805b horns. I have also used 1005 horns but lost a little imaging in the process. For the network, I am using ALK's network.

I would be curious if anyone else has incorporated the T-350's and what their opinion is.

[sunnysal]

glad to hear you are nejoying the 45 wolfram. nice amps to choose from indeed! I assume they run out of steam at some point, give us some feedback about loud listening and demanding music on those amps, when they run out of steam, etc. thanks, tony

[dubai2000]

Well Tony, I know it sounds incredible, but in my room they play loud enough for all kinds of music, be it Led Zep or Mahler's 8th symphony. But then I do live in an apartment with neighbours (who are quite tolerant btw.).

Let's put it this way, in a room that is bigger than mine (we are talking about 20 square meter of listening space) I CAN imagine that there will be a limit to loudness, but fortunately they work fine for me. Plus remember that they are sub supported which might make a difference as well. I know that they are loud enough to entertain people in the garden downstairs (I am one up) with the balcony door open . Sorry, not very specific, but perhaps it gives you some idea .

Wolfram