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Author Topic: Tape Project Repro Amp #1 initial impressions  (Read 10386 times)

Offline ironbut

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Tape Project Repro Amp #1 initial impressions
« on: July 04, 2007, 02:54:54 AM »
A couple of months ago Doc mentioned that he was selling his personal repro amp. I'd been saving for one of the first production run and after a couple of emails, sent off a deposit for it. For any of you guys that were at the Stereophile show in NY, it was the one in the TAD room. To preface this preview, I've been using a modded Seduction with my Technics RS1500 for a while now and have been pretty happy with it warts and all. Aside from the mods of the RIAA to NAB/IEC, it is bone stock. The main drawback with it is a lack of gain. To remedy this, I fed it to an old GAS preamp I keep as a backup. I'm pretty purist, audio wise, so the extra piece of gear, not to mention the extra ic, goes against my preferences. When I first hooked the Seduction directly to the playback selector switch on my deck, I noticed a loss of details and a slight roll-off of the highs. That bothered me for about 1 tape's worth. It was in a whole different league as far as being musical and pleasing to the ear, there was never a thought of turning back. Gone was the etched class a/b, '70's, spec war sound. The Seduction seemed to do a good job on the things that I find special about tape, texture and presence. Presence is the fleshing out of a sonic image for a long enough time to make that image believable. It's not enough for say, the snap of a woodblock to be precise, it's also the echos of that snap that give it "place" resulting sometimes in
 presence. And, it's not enough to just hear it, there needs to be a connection to some sonic memory for presence to be complete. So, I think that everyone perception of presence is a bit different. One things for sure though, it either has it, or it doesn't. There's no degrees. Only the number of times it occurs in a time frame can really be measured and only for that individual.
Well,.. the lectures over. On to the repro amp.
First off, the details are back in a big way! If you listen into a thickly scored selection, you can hear instruments you had no idea were there before. On Gould's Latin American Sym. I always thought there was something weird about the guitar on the last movement. On the Seduction, you can tell it's a guitar being strummed. With the stock electronics you had to really listen to differentiate it from another type of strummed instrument. With the repo amp, I could tell that the player was using some sort of pick to strum the instrument ( probably to bring the volume up, latin american my ass! ). You also get all the usual audiophile stuff like creaking chairs, mutes being kicked over etc..It isn't distracting, you have to listen for it just like in real life.
The bottom end is textured and deep. But it doesn't obscure the mids. On the same Gould, there are some big whacks of the bass drum that shudders for what seems like forever, and on the same impact is a repeating figure on the marimbas. With the repro amp, even at the moment the mallet strikes the skin, the note of the marimba is still clearly audible to lead you back down the path of that repeating figure. I honestly doubt that you'd be able to hear that first note without the aid of some well place microphones.
Which brings us to dynamics. This thing can really cut loose when the moments right. The dynamic swing is large. I think I'd need to hear some of the Tape Project catalog to really know how big a swing it is. I have noticed a little fuzz in the upper mid-lower treble when things get intense. I'll try and tube roll this out. The source could also be upstream and is now revealed by this preamp.
So, what about this presence thing I was rambling on about? ( thought about skipping over it just for fun) I've listened to about 10 Barclay-Crockers now (some several times) and those magic moments keep happening over and over. Even on some tapes that are otherwise unremarkable. An oboe will pop out of the crowd or something will hit the floor and I'll turn around it see if I'm still alone. Spooky! To me, this alone is worth the price of admission.
So, I know what some of you guys are thinking," here he goes again, cheerleading the Tape Project". Well, I can't deny that my enthusiasm translates into some posts that are a little over the top, but this repro amp has exceeded my hopes and laid to rest any buyer remorse ( thank god!). Now, I can't wait to get some of those tapes and the extended response heads and,..
Next installment- tube rolling

« Last Edit: August 12, 2008, 11:02:28 AM by ironbut »
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Offline docb

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Re: Tape Project Repo Amp #1 initial impressions
« Reply #1 on: July 04, 2007, 11:21:28 AM »
Wow, thanks Steve! The ironic back story is that the basic front end circuit that we use in the Repro was a design we rejected when we started developing the Seduction phono preamp. Since the Sed had a budget in mind we didn't use active loads and shunt regulation like the Repro has, and consequently we all (PJ, Ed and I) found it a little too tubey. Somewhere along the line I ended up with the POC prototype, which Ed had built. Ed had put in a shunt regulator, PJ worked up the circuit changes needed and I modded it with active loads and we gave it another listen. It was really, really good on vinyl, so we decided to mod the EQ and use it for Repro. Steve will notice on the front panel of the prototype that I had actually added a selector position for phono. We later determined that incorporating an RIAA setting would create a bit of a gain compromise, so the production unit won't have that capability. But there will be a phono only version of the preamp coming out after we get through the final hurdles with the Tape Project. I think it might really be da' bomb for LPs.

I suspect the slight fizz is in the tubes as you suggest. As in our kits I ship with reliable, obtainable current production tubes. For all out performance I would definitely shoot for some really spiffy EF86 types and a gold pin 7308. That's what we used at the shows. They can be smoother and have better resolution at the same time. But beware that finding quiet old stock tubes can be frustrating. Out of my modest batch of such tubes I really only have a few that are quiet enough.
Dan "Doc B." Schmalle
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Managing Director - retired, The Tape Project

Offline tapepath

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Re: Tape Project Repo Amp #1 initial impressions
« Reply #2 on: July 05, 2007, 10:15:31 AM »
Thanks, Steve! Very helpful review, well described.

Offline ironbut

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Re: Tape Project Repo Amp #1 initial impressions
« Reply #3 on: July 06, 2007, 09:38:29 PM »
Just a quick update,.. the fuzz I was hearing in the upper mids to highs was tube related. I've thrown the BC Koday Duo tape ( top registers of the cello were where it started ) which has a section that is almost "needling" the "tender spot". Not a single electronic or mechanical anomaly. I'm listening to the BC Holst Planets and while it's not exactly my fav' reading, it does kick some major ass dynamics wise. The percussion sounds absolutely amazing!
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Offline DRCope

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Re: Tape Project Repo Amp #1 initial impressions
« Reply #4 on: July 10, 2007, 04:05:57 PM »
So, Steve, no has asked the really important question here: What are you going to do with your tape-EQ'd Seduction? ;-)

I'm amassing quite a few 7" 7 1/2ips tapes here, a couple two track in-line, one binaural, but listening is still through my Otari MX5050's standard playback electronics, and that just can't go on for much longer . . . .

Also just bought the Albeniz on LP and the Arnold Overtures on CD to get a feel for the music and recordings. The TP tapes are calling me, but while I believe they are worth every penny, my pennies aren't stacked high enough without major inspiration!!
Moving from hifi show exhibitor to producing new, analog recordings of small classical, jazz, blues, folk/roots music.

The gear just got bigger and heavier. Who knew?!

Offline ironbut

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Re: Tape Project Repo Amp #1 initial impressions
« Reply #5 on: July 10, 2007, 05:31:29 PM »
So, Steve, no has asked the really important question here: What are you going to do with your tape-EQ'd Seduction? ;-)

Hmm, I haven't really given that any serious thought. I probably will sell it. Just not at this exact time. Perhaps next month sometime. If you like, I'll PM you when I decide to. I think any further discussion would be best with PM's anyway.

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Offline ironbut

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Re: Tape Project Repro Amp #1 Tube Rolling
« Reply #6 on: August 19, 2007, 06:35:56 PM »
It sounds like a few lucky tape heads will be getting their repro amps pretty soon so here goes,..
This is something that I always take my own sweet time doing. When I first get tubes, whether NOS or used, I give them at least 4 hours of warm up without a signal applied. Clean the pins. Than I give them about 10 hours with music before I get critical. This isn't to deny that the first impressions of fresh out of the box tubes doesn't give you a pretty good idea of what they'll sound like. Some sonic characteristics are more likely than others to fade with burn-in while others don't show up till many hours of listening have gone by. Usually, the latter are pretty subtle and have more to do with soundstage and imaging.

In the spirit of full discloser, I am new to EF86 type tubes. The repo amp uses a pair of these. I do have extensive experience with 6dj8/6922/7308's. My favorites are white label Amperex PQ (2 star) early '60's ,usa 7308's. The amp uses one of these and that's what I used to evaluate the EF86's. Be aware, we are working with a very small signal here. And, not unlike a MC phono stage, you need to get the quietest tubes you can. I started out buying a bunch of Ebay cheapo tubes hoping to weed out the ones that aren't worthy candidates, and ended up with a box of boat anchors. I have no doubt that some of these might be fine in other less critical applications.
I bought a pair of all the current production EF86 types that I know of. These are Svetlana EF86, JJ EF806s, Tung-sol (labeled) EF806sg, Electro Harmonics EF86.
Because gain and noise are so important in this application I'll use a 1-10 scale.

The Svet's came stock. Noise floor-4.5   Listening level 4
This isn't that shabby sounding a tube. It's fairly balanced, has an extended high end, and it's faults aren't too prominent. I does have a laundry list of problems. The highs are a bit glassy and get hard during loud passages. Notes decay is a little short lived and combined with a recessed bass, it lacks fullness and body. After reading that, you might think that this tube sucks, but like I said, these problems aren't in your face all the time so, for the money, it's quiet and will make your better tapes sound as good as a $5k CD player.

JJ EF806s This tube is a newcomer to these shores at least. Costs twice as much as the Svet or the EH but man, talk about poor quality. PeeUuw! The pins are so rough and irregular that I can't imagine that anyone at the factory actually looks at these before shipping. I had to do all kinds of stuff to get decent contact with the socket. And when finally did, the gain was so low that I can't imagine that this is normal. So,..
Noise floor-I honestly don't know
Listening level 7
Because of the self noise of everything else, I was trying to listen through a gale. Why would I bother to include this tube? Because somewhere down there, I could hear a pretty nice tube. I have an email off to JJ Industries and I hope that this is just a defective pair. If it had the gain of the rest of these tubes, I'm pretty sure it would win the current production race.

Electro Harmonics EF86-Noise floor 3.75 listening level 4
As you can see, there is a bit of noise audible when theres no music, but that's when there's No music. In practical terms, it's a dead heat which means no issue. This one's pretty balanced as well. Not allot of bass but what's there is pretty textured and tuneful. There's a glare in the upper mids to treble that obscures fine detail. Really cut from the same cloth as the Svet. Nice heavy glass and good workmanship.

Tung-sol EF806sg labeled - noise floor 4.2 listening level 4
Identical to the EH cosmetically , but as you can see, obviously not. Very quiet. It also doesn't have as much of the midrange glare so the details are a bit better. Extension at both ends is better too but the bass still lacks weight. I was thinking that this would be a good current production tube when I decided to take one more listen before I recommended it. About 2 hours into the listening, one of the tubes went noisy. It brought the noise up so it's audible during quiet passages. Of course it is 5 days out of warranty but the dealer I got them from just emailed me that he would replace it. I'd heard that this could happen with these tubes ( early production growing pains I hope) but I was hoping that they'd worked that out by now. I guess not.
 
I didn't mention above that I made my final evaluations of these tubes with NO Barclay-Crocker tapes! I'm sure this will come as a shock to folks who know what a fan I am of these tapes. But, I still have to mod my Dolby decoder so I used 2 track Mercuries and 4 track Verve non Dolby encoded tapes so the sound wouldn't be influenced by decoding or lack there-of.

NOS tubes
All of the dumpster fodder I got would have been here. I did find one real jewel,..

Valvo E80F pinch waist, d getter, red print- The E80F is a low noise variant that was developed for medical/magnetics use. Most were made by Phillips in their various labels, Valvo, Miniwatt,Amperex, Dario etc.. They seem pretty plentiful especially from continental tube sellers. Pretty cheap too but once again, pick your sellers wisely.
Noise floor -4 listening level-4.2 once again close enough ( when I do these levels it is in a very quiet room on headphones ) Fantastic bass. Textured, extended and warm. Real tube type bass. While listening to a Mercury 2 track  Debussy's Iberia ( Paray) there was plenty of impact while the instrumental separation and ability to follow a line is totally natural. This is a tube lovers sound. The presentation is involving, emotional, and joyous when appropriate. During passages with a building tension, I find myself holding my breath till the moment of melodic resolution. There is nothing hard or offensive in this tube.  Of course, it's not all peaches and cream. That warm euphonic bass can be a little much especially on something like the Verve Gerry Mulligan at the Village Vanguard. The treble lacks a bit of sparkle too. I found that using a pair of Herbies tube dampers just below midway did wonders on both of these issues. Other tiny issues exist. They are pretty sensitive to rfi. Proper positioning of the amp will remedy this but if you are planning on using the rack/cabinet it will limit your choices. Also, the E80f is a longer tube ( think 6cg7) than other ef86's. They need longer tube shields if you use them. These do seem to take longer to warm up and sound their best from most other tubes. I found it takes about 45 min for the bass to tighten up all proper like. But considering that I paid about $20 each for mine (that seems to be the going rate for non pinch waist E80f nos on Ebay) I can't imagine why you'd mess with the current production. BTW this is a premium 10,000 hour tube!
Lush tube warmth. Great impact. Cheap. Long life. What more could you ask for?
Well, for a walk on the other side of the tube lined street we have,...

THE Telefunken EF806s! Very rare. Very Expensive. A legendary tube if ever there was one.
Noise floor-4  Listening level 4
Noise is a non-issue here. The regular Telefunken gray plate EF86's are supposed to be pretty low noise too. Those are one of the terrible ebay scores I made. While looking for a better pair I found a NIB pair of 806s'. I knew I'd always wonder if I didn't buy a pair and Man, am I glad I did! I don't think I've ever heard a better tube than these. Period!  Aside from a slightly tubey sounding deep bass ( and I mean deeeep) and a sweetness in the upper mids to the highs, these guys are the mythical "straight wire with gain"! The clarity is just amazing. I don't think there is any detail left to be heard on the 15 tapes I've listened to so far. Tympani hits are so defined and have so much impact that you're torn between which you should focus on. The midrange and highs are just open. Not more or less open,.. OPEN! At first, there was a little hardness to the violins at full voice but after about 10 hours that faded away. And when a soloist decides to take a passage at twice the normal speed, there's no blurring of the notes. Did I say that they have amazing clarity?  And there's an effortlessness to the presentation. Allot of the time, when gear has this level of resolution, there's a trade off. Bleached out upper mids, lean tone. Nope! There's a rich tone and fullness top to bottom.  I don't know if I ever heard such a huge gulf between the great and the best in components. I usually have to listen closely over and over to be sure that I'm not imagining a difference. This is just a matter of putting it into words. They are also 10,000 hr + tubes. These are THE tubes for the Repro Amp no question about it. Are they worth the money?  Well, the repo amp ain't cheap. And, I've always thought that this whole thing is about the best source. Get em while you can. Scarce, scarce, scarce,..
« Last Edit: August 12, 2008, 11:04:28 AM by ironbut »
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Offline ironbut

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Re: Tape Project Repro Amp #1 initial impressions
« Reply #7 on: August 12, 2008, 11:57:57 AM »
I thought I'd revive this old thread for the benefit of new Repro amp owners. I can't friggin' believe that it's been a year since I wrote these reviewettes.
Well, like I said, I've owned the Repro for a year now and I'm still just as enthusiastic about it as the day I got it. I wouldn't say that extended burn in has changed anything but this was the amp that Doc and Co. used to for the early demos at CES and the NY Stereophile shows so it had quite a bit of time on it when I got it. I'm sure that the caps in the new ones would continue to improve for the first several hundred hours or so.
As far as the tubes go, the only changes I've made have been the use of a Holland production Amperex 7308 (1960's Dario labeled) as apposed to the US (Duffy Ave NY) one that I used in the above impressions. I think the Holland production tube has a more balanced mid bass but that's about the only difference (I got a great deal on it since almost all the label was worn off).
The Telefunken EF806s remains my reference and until something really special comes along, it'll hold onto the back up stock that I've collected. They're quiet, smooth and have no glaring errors that call attention to themselves. The bottom line for me is that this tube set has made further tube rolling a non issue.
So, I think what I can add to this old thread is a little experience buying these tubes and how to minimize the damage to your wallet. The first pair I bought was $300 a matched pair. Yup,.. that figure curled my toes too but I wanted to have a reference point so I got them from a tube store that I've dealt with many times and made sure they were well tested. I've actually seen these tubes go for more,.. a lot more, but I think you guys can do better. What I've found has been that these tubes aren't as rare as I originally believed. Of course that's all very relative and it depends on your tube hunting experience. Just don't jump at the first pair you see if it's selling for crazy $$$ because another pair will come along in a month or so. It seem like the normal decent price is around $100 each. That's in original boxes too. I've bought ones that are unlabeled and unboxed and (at least the 4 I have) they are the real thing but at a considerable savings. As long as the tubes have the diamond on the bottom (as most TFK's do) I think you're safe on buying them. Just be sure they've been tested so you don't get a used pair when you're paying new dollars.
If you guys have tried tubes that you love, please jump in and tell us about them. I'm all ears.
steve koto
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Offline jcmusic

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Re: Tape Project Repro Amp #1 initial impressions
« Reply #8 on: August 12, 2008, 02:54:33 PM »
Hi Steve,
I happen to have a few tubes in that family that I don't use, I for sure have a nice pair of Amerex 7308's that I will never use. Also some 6922's and others. In my equipment I use the Amperex 6DJ8
a-frams and really like them, also have some nice Siemmens.

Jay
Redpoint Model D TT/Soundsmith Sotto Voce Cartridge Otari MX 5050 BII/BH Tube Repro deHavilland Model 222
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Offline ironbut

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Re: Tape Project Repro Amp #1 initial impressions
« Reply #9 on: November 18, 2008, 12:29:40 AM »
A couple of months ago I got a pair of MOV (GEC) CV4085's. When I was searching around for impressions of different EF86's there was a faction of posters that had a strong preference for the GEC Z729. They tended to be owners of Quad amps but I kept an eye out for some but never saw what looked like a reasonable pair to try. When looking for some totally different tubes I stumbled across this pair of CV4085's which are (I've heard) military select versions of the Z729's. I always give the better tubes a good long time before I post any solid impressions and since these were NOS, I wanted to be sure there was at least 50 hours on them before I reported my impressions of them in my Repro amp. I'm still using the Heerlen production Amperex 7308 and GE 6cm7's. The cables I'm using are both from Silver Audio- the heads to Repro is a Silver Breeze phono  and the Repro to preamp is an Appassionata.
First, these tubes are very quiet, maybe a touch quieter than the TFK ef806s (my reference tubes). They have very good gain and seem pretty rugged (don't seem microphonic when touching them while active). The frequency extension is just as good as the Telefunkens which is excellent. I'm obviously not sure about the longevity of this tube but they are a little cheaper than your average 806s (a pair of Z729's usually go for under $200).
So, which one is better? This is a matter of taste, both in sound and music I believe. The Telefunkens are smooth sounding but are very accurate (maybe a little soft on the bottom). The GEC's are euphonic and makes some selections sound better than they actually are. This is most apparent on the Robert Cray TP#004. The sound of these tubes really gets your toes tapping with a slightly bloomy bass that is a little forward in the mix. Electric guitars are more fluid sounding but clean at the same time. When I first got the GEC's I though the bass was a tad thick and obscured the lower midrange a little but after 25 hours or thereabouts, the bass tightened up a bit but is still forward. This tube works so well with amplified instruments that if that's your thing, I think it is a must try. On small combo jazz or classical works, I think the focus moves onto detailing and soundstage more than shear guts and I still feel that this music is better served by the TFK. But, if you shelled out the bucks for one of Doc's Repro Amps, I really think that you owe it to yourself to have a pair of each. I'm not sure if the CV4085 is quieter than the Z729 but they are structurally identical. They are both easier to find than the TFK EF806s and like I said, should be less than $200 a pair.
So in the top tier of input tubes for the Repro, now there are two. Which is your "bag" depends on how you was raised,.. Rockin or Bachin.
« Last Edit: November 18, 2008, 09:27:49 PM by ironbut »
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Offline Ben

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Re: Tape Project Repro Amp #1 initial impressions
« Reply #10 on: November 18, 2008, 08:31:13 PM »
Latin
Guantanamera - The Sandpipers.
It can be found on LP,CD & 7.5" tape. From my distant memory
better than LP.
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Offline steveidosound

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Re: Tape Project Repro Amp #1 initial impressions
« Reply #11 on: November 19, 2008, 01:05:22 AM »
F.W.I.W. dept. -   I have had the 45 single of that since I was a pup in school and the song was new.
It (now) does not sound better than anything including an mp3  ;)
It is in Spanish. From Cuba actually. Pete Seeger had something to do with collecting it.
Which brings me completely off topic to wouldn't it be nice to have some Weavers material from the Vanguard era on TP tape !
« Last Edit: November 19, 2008, 01:36:39 AM by steveidosound »
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