Passive Line Drive or Tube Preamp?

jdjohn

I have a McCormack DNA 125 driving my SDA-2Bs, but I'm considering a 'new-to-me' preamp. I'm torn between a passive line drive pre and a tube pre. Then 'if' a tube pre is the decision, how about an updated Dynaco PAS-3X vs a new Aric Audio Expression? TIA for any input.

breal74

I am curious to hear others thoughts on this as well. Anyone?

Jim Shearer

Since no one has commented thus far…

Do you want to experiment on the cheap? For a passive, you might try the one I use on my dynakitparts.com ST-35 (which has very high input impedance): Schiit SYS:
http://schiit.com/products/sys
Works just fine for me, but then all I need are the two inputs.

For my Pass ACA mono blocks (which are relatively low input impedance) I need a buffer, so I bought this cheap Chinese knock-off of a Matisse (sp?) circuit:
https://www.amazon.com/SainSmart-Assembled-Headphone-Amplifier-Transformer/dp/B008BGLN5G/ref=pd_ybh_a_57?ie=UTF8&psc=1&refRID=5DDNZBWHF67YDR8N6ERP
However: there are several caveats!
—the transformer that comes with it assumes 110v input; most places have 120 to 125 v at the wall socket—quick & dirty fix is to put a 1 ohm, 5 watt resistor in series with the ‘6.3 v’ input to drop the heater voltage to correct level; for the short term, you can ignore the excess voltage to the plates. In the long term, I suspect that the electrolytic caps will fail due to excess voltage, as they are marginal at best.
—Throw out the tubes it comes with & buy NOS JAN 5670W—I got them from Tube Depot for $4.95 each.
—Remember to twist the wires from the transformer to the board inputs to reduce hum!
—You can get away without a power switch by cutting up an old extension cord, using wire nuts, and just plugging it in when needed.
—There is a mistake on the board which can be corrected by cutting a trace on the back of the board; it will work as is, but the rectifier for the heaters will run HOT; there is a long thread on AudioKarma which includes info on this.
—You can run it w/o a case, but BE CAREFUL! Children, pets, and curious adult fingers MUST be kept away from the exposed electronics because of HIGH VOLTAGE! It MIGHT not kill you, but it would at the very least be a hard & painful lesson!

tonyb

Personally, I think tubed pre as I'm not a fan of anything Dynaco. The cheap Chinese brands are doable on a budget, or you can look at some vintage stuff on the cheap like Conrad Johnson, Cary DJH and the likes.

If you want to stay SS, your options are plenty. Any particular reason you want to stay passive on that end ?

MrBuhl

I am not familiar with your preamp choices, but having run four different tube pre-amps with my DNA-1, I can highly recommend the sound! I've used a Bottlehead Foreplay, Audible Illusions Modulus 1, Dodd Mid Level, and the Backert Labs Rhumba. They are all fantastic honestly, the the Dodd has been my favorite for its black background.

jdjohn

Thanks for the input. I think the tube route is where I want to go, and for budget, I'm between the cheap Chinese products with extensive mods (but thanks for that info, Jim), but less than the very fine products MrBuhl listed.

tony, the passive idea came from a suggestion in another forum about the McCormack TLC Line Drive preamp; I know Steve McCormack also made the Mod Squad passives as well. The idea there was to remove voicing from any type of pre. But again, I think I want to try a tube at this point based on what I've read, esp after MrBuhl praising the tube pre/McCormack DNA combo.

So tony, you suggest I avoid the Dynaco tube preamps like the PAS 3 or 4?
A used Jolida JD5T has also come into the picture now.

heiney9

I have an Eastern Electric Mini Max tube pre that I am preparing to sell. Not sure what your budget is, but it will come with a nice assortment of tubes to get the full tube rolling experience.

It punches was above it's price point and would mate up well with McCormack gear.

Do a Google search on it, there's lots of info out there. I recently bought the flagship Eastern Electric tube pre so I don't have any need for it anymore.

Just throwing it out there since you are considering a tube pre, this one will really give you a nice introduction to tubes and tube rolling for not a lot of money. It's a superb sounding unit and built very, very well.

Let me know if your interested and I'll give you more details, etc. via PM.

H9

jdjohn

That EE MiniMax looks like a nice one, heiney. Thanks for mentioning it. I see that they went for well over a grand when initially released, but my budget is maybe half of that...just to let you know where I'm at with this purchase.

Nightfall

http://www.ebay.com/itm/Mint-demo-unit-of-Dared-SL-2000A-pure-tube-preamp-line-stage-w-remote-/262513256503?hash=item3d1f026837:m:mU9SxPCB9qTubi_8p8h0LGA

jdjohn

Well I guess someone here liked that Dared...it sold tonight.

dkfreebird

I'm running the Dared 2000a with my McCormack Dna 0.5 Deluxe and love it.I picked up a Parasound 2100 pre to try out with it and it sounds good to but I just use it during the week.When I get ready to listen to my system during the weekend when I can really enjoy it the tubes come in and it is bliss.The Dared is a great start into tubes and I will eventually move up the chain.

heiney9

I started with a Dared SL2000A, still one of the best audio deals going especially when you start rolling better tubes.

Yes, the Minimax is going to be slightly over your initial budget. If you can raise your budget to around $750 that's what I'm asking for the Mini Max w/ a nice selection of tubes.

H9

tonyb

The passives I would heap praise on don't come in that budget range. I would give the Dodd a whirl any day. Least with tubes you can adjust the sound somewhat to your preferences with rolling different ones.

I know Dynaco has a following, but I've never heard a piece of theirs that said "gotta have it". The only ones I've heard that were decent were one's pretty well modified. Stock units may leave you wanting. Just my opinion of course.

jdjohn

Heiney, thanks for considering me on the MiniMax. If my budget expands, I'll keep this in mind Btw, I saw your old review of the Dared SL2000A on audioreview.com. Clearly you liked it then, and good to know it's still on your recommended list.

Dodd's appear to be somewhat rare, and the listings I have seen are a little too pricey for me as an intro tube pre. Looks like many of their models are battery-powered.

Yeah, tony, those Dynacos are popular candidates for modding...so much so that it seems the chassis is the only original part remaining on many of them when complete. I don't really want to tackle a project like that right now. I've also read that they can have impedance matching issues with many power amps. I think they have a higher output impedance than is typically desired??? The McCormack looks like it has 100kohm input impedance.

Any Jolida JD5T love out there??? I like the fact that they can be stacked (no exposed tubes), but I have to admit exposed tubes are kinda sexy, so I'm a little torn on this one since used ones are in my price range.

ZLTFUL

Passive pre's are such a gamble scenario. There are good ones out there, but as Bud pointed out, they don't come cheap. The small handful of good passive pres in what would be considered a budget range are rare and hard to come by. I had a chance at one before I picked up my Cary SLP-03 but passed on it to go with something more "known".

Good luck with your search but I think tubed pre is the way to go.

voltz

I also have the Dared SL-2000A preamp
paired with the Dared VP-300B 9-wpc Mono-blocks
for use with my Omega Super 7 full range speakers
I had this set up at LSAF this year

txcoastal1

^^^^This system was extremely fun to listen too. The last night at LSAF had several key Texas audiophiles that were impressed at that the bang for the buck setup, my liver is still recovering from that night

MrBuhl

Those EE MiniMax are serious stuff, I have the tube CDP and it's grossly overbuilt and has a beautiful sound. They get amazing reviews as well.

The Dodds are very rare, glad I jumped on my two when they came around because they seem to be rare as hens teeth lately.

FWIW, the Bottlehead Foreplay (with upgrades) i found on AG for about half your budget. It's not a perfect solution, but it has filled in (surprisingly admirably) at that price point and while I worked up the courage to have someone sort out the Dodd I blew up.

Nightfall

If you want to spend a little more along the lines of the EE there's also the Dared MC-7P, which is the one I use. More inputs as well as a tubed phono stage and two preouts in case you want to use a sub.

jdjohn

MrBuhl wrote: »

FWIW, the Bottlehead Foreplay (with upgrades) i found on AG for about half your budget. It's not a perfect solution, but it has filled in (surprisingly admirably) at that price point and while I worked up the courage to have someone sort out the Dodd I blew up.

I need two RCA outputs, so a bit limited in choices, but keeping an eye out! Hmmm...'the Dodd I blew up"...I think there's a story there...

Nightfall wrote: »

If you want to spend a little more along the lines of the EE there's also the Dared MC-7P, which is the one I use. More inputs as well as a tubed phono stage and two preouts in case you want to use a sub.

Damn that is sexy. It seems that the aftermarket for Dared is currently very dry...probably because everyone is loving theirs. Preamps are especially rare at the moment. I'm contemplating a mid-level Chinese piece right now as an entry-level compromise.

heiney9

The Mini Max has two outputs.............and with the assortment of tubes I'm including you will be set for awhile on the tube rolling front.

You do realize that tube rolling is very fun and beneficial, especially with a tubed pre-amp. You'll be spending hundreds more buying tubes to roll. . Am I helping? Lol.

What mid level Chinese piece are you considering? You need to be careful and make sure it's a decent unit and it uses commonly found tubes, not some arbitrary tube that only 1 or 2 manufactures make. Tube rolling is 1/2 the fun of having tube gear.

Also, I highly recommend if it is tube rectified. You can get better tone when a pre-amp uses a tube based rectifier vs. a standard solid state rectifier. The difference is startling and desirable. (The Mini Max has a tube rectifier )

If you could only raise the budget.

H9

jdjohn

Yep, I know about 'tube rolling'. Who knew that Russian tubes would be such a hot commodity? Maybe I should call you Heiney The Tempter

Anyway, here's one I'm following. http://www.ebay.com/itm/261018869655?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT It uses 12AU7, 12AT7 (both standard), and two 6Z4 rectifier tubes, which although not too common, seem to be available. And it has the world famous Shigeru Wada style circuit Haha...is that even a thing? Doubt it.

Here's another one. http://www.ebay.com/itm/291792795663?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT It uses 6N1 & 6N2, which seem to be rather oddball, and again the 6Z4. But...it looks like 6922 can be used for those 6N1&2???

Now here's a Jim Fosgate custom-made job using that same Music Angel chassis, but it only has one single 6922 tube, so I guess a SS rectifier. But it's Jim Fosgate!!! PTP wiring in it. http://www.ebay.com/itm/122053334306?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Then at the top of my budget is this hand-made (again PTP wiring) unit made by Aric Audio. http://aricaudio.com/products.php?product=EXP100#desc It can take a few different line tubes, and uses an OD3 gas-charged regulator tube, but no rectifier tube.

Thanks for your help and advice, guys.

heiney9

6922 really can't be used in place of a 6N1 or 6N2. Older Russian 6n1's are decent enough and plentiful. You can use an ECC85 in place of a 6N1 as I have a tube integrated that uses them . The ECC85 is used in a lot of tuner circuits so they are plentiful and a decent variety to choose from. Although there are only about 6-7 manufacturer's that make them all, regardless of the brand label on the tube.

I'd do some serious research on the 6N2 and the particular unit you are looking at. The 6922/6DJ8 variants rarely work without circuit modification. Not really worth the headache if you ask me.

Lots of 12AU7 and 12AT7 and variants. So your safe there.

mikeyb128

To be honest if I were you, I would be patient, sell a few things and buy that mini max H9 has. It will outperform anything you have mentioned. Plus you will be getting a stash of tubes with it. 250 bucks isn't much more than 500$. And I'm sure he might be open to reasonable offers, you two could work something out.

heiney9

Actually the Mini Max is so good that I really wanted to hang on to it. But since I bought the Eastern Electric Avant tube pre for even more $$$, I told myself I'd sell the Mini Max to fund the new one.

I really was extremely happy with the Mini Max, but the Avant does better it, not Earth shattering better, but it does. It also uses 8 tubes instead of 3 so much more expense there as well.

H9

jdjohn

They have some very nice gear there DSkip...a little over my budget though.
I think patience will be key as mikeyb has said. And yes, I do need to sell some gear.

I'm not forgetting about the EE MiniMax, but I did see an Audible Illusion Modulus on eBay. Starting bid is $300, but nine days to go on the auction.

Irrenhaus

I have the AES (Cary) AE3 and like it a lot. Paired with a Parasound 2125. Not very expensive.


Cheers

MrBuhl

jdjohn wrote: »

but I did see an Audible Illusion Modulus on eBay. Starting bid is $300, but nine days to go on the auction.

That'll be a steal on an AI, likely will go higher but worth a watch. FWIW i have found mine to be pretty tube picky, as in, there's only one tube I have really liked in it that lasts more than a few months... YMMV, I know others have had better luck, also there are mods that will take care of that issue.

jdjohn

MrBuhl wrote: »

That'll be a steal on an AI, likely will go higher but worth a watch. FWIW i have found mine to be pretty tube picky, as in, there's only one tube I have really liked in it that lasts more than a few months... YMMV, I know others have had better luck, also there are mods that will take care of that issue.

I have read they can be 'tube hungry', especially the ones with phono stage...which this one has

tonyb

Irrenhaus wrote: »

I have the AES (Cary) AE3 and like it a lot. Paired with a Parasound 2125. Not very expensive.


Cheers

....and a sweet one it is. The DJH version even better. If you ever want to move it on, give me a yell.

jdjohn

Patience paid off. Another Dared SL-2000A came up on eBay, so I pounced on it. $399 plus shipping, which was within my budget, so I'm feeling good about it
Thanks for all your patience with me and my questions.