Bottlehead Repro Tube Head Amp vs Cello/King

audioblazer

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Mark,

Its sound very much like tube rush- like rushing air sound. I m not sure whether tube noise quieten down or get noisier over time. What I was told is that telefunken ef 806s or ef 86 tends to be noisier. As I understand from Dan of Bottlehead, with burnt in of the cathode of the tube, it may quieten down after 50 hours of play or so. I suppose maybe u knw better. Thanks for the info
 

jdza

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May 3, 2010
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Anyone do any mods to their Tube Repro? Like trying different caps etc, etc???

Jay

I do not own a Tube Repro but recently bought an Eros kit,mainly out of curiousity. As I understand it the Eros is very similar to the Repro if the Repro is used with its RCA outputs.I had the Eros professionally built by an RF engineer who took thorough care with layout etc. Typical audiophile -all film caps were substituted with Mundorf silver/gold in oil and teflons and wiring with a wire I have had much success with. On completion this thing sounded fuzzy and murky even after days. Just about ready to pull it permanently from the system I remember a curiosity we found whilst testing it. The builder used a frequency generator through a step down transformer for testing. Sine waves appeared fuzzy on a scope but when we swapped the leads on the step down transformer it was perfect-we blamed the transformer. So swapping the "pos /neg"direct head outputs from the Studer I tried again. Suddenly the sound became focused and detailed- much more than I have previously experienced with absolute phase switching.

The unit still had a tube rush as described above and sounded dark and too warm for my tastes. My RF mate then suggested substituting the EF 86 tubes(High quality Soviet era military tubes not the supplied ones) with EF 804S tubes.Note these are not direct swaps as although they are electrically identical pin out is different. Suddenly the rush disappeared and more surprising the sound took a giant leap forward .This funky little kit now sounds awesome.Bass is tight and deep ,trebles shimmer and the bloated mids is now razor sharp and tightly focused. I just cannot believe it is that same little amp.
 
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audioblazer

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Jdza,

Telefunken ef 804s? U meant telefunken ef 806s ? Anyway, to confirm my suspicious that the noisy tube rush I heard is due to ef 806s, I purchased a pair of ef 806s thru ebay germany and when I replaced my existing ef 806s with the newly purchased ef 806s to play my newly acquired TP10 saxaphone colossus, it was very quiet but unfortunately 1 of the tube was defective and I dont get any sound from that channel. Looks like I got to try it with GEC CV 4085 and see how it goes.
Back to the hunt for tube again
 

jdza

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No,I mean EF 804S. It was designed by Telefunken as an improvement on the 86/806. To deal with issues of noise and capacitance they moved the heater filaments to different pins,hence the need for a rewire.Reportedly this tube is what gave the Beatles their superior sound as Abbey Road at the insistance of George Martin changed the EF 806 in their Telefunken mic amps to 804s. No idea if that bit is true but it makes a good story.
 

audioblazer

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jdza, thks for the clarification. Maybe I should try this tube and see how it goes compared to TFK EF 806s
 

tony ky ma

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Aug 21, 2010
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I did in studer A810. most of the studer's amp is SS exceipt C37, A810 almost IC only, I mod the repro amp's out put section into to tube 5687 mu stage, with a switch that can switch back for compare, the answere was tube won all, and I will do more mods later
 

deeng

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Aug 27, 2010
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Hi,

I'm new to this site and late to this thread... I am using a Studer A80 with the Tape Project tapes. I suspected my electronics could be improved upon when the tapes didn't sound better that their vinyl equivalent. I was looking at the Tube repro and the Aria. I ultimately chose the Aria because of tube rush noise. The Aria was a huge improvement in soundstage and high frequencies. I feel like I'm hearing what others have been hearing on the TP tapes.

Scott
 

jcmusic

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May 20, 2010
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Hi and welcome to the forum, it sounds a bit strange to me that your TP tapes didn't sound any better than the LP's. Now I understand about the electronics of a stock machine but, I think they still shold have sounded better than the LP's. Tell us more about the Aria?

Jay
 

audioblazer

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I have an interesting discovery. My set up , Studer A810 with tube repro has a very audible humming on the left channel or right channel depending how I wired my interconnect fr Studer to Repro. Initially I thought the problem was due to noisy Tef Ef 806s and I purchased 4 pairs to experiment and still I have the same humming sound. Fortunately thru some trouble shooting and guidance fr Doc of Tapeproject, I managed to solve the humming issue by connecting a ground wire from Studer to repro. Problem solved
 
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jcmusic

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May 20, 2010
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Just Outside New Orleans, La.
I have an interesting discovery. My set up , Studer A810 with tube repro has a very audible humming on the left channel or right channel depending how I wired my interconnect fr Studer to Repro. Initially I thought the problem was due to noisy Tef Ef 806s and I purchased 4 pairs to experiment and still I have the same humming sound. Fortunately thru some trouble shooting and guidance fr Doc of Tapeproject, I managed to solve the humming issue by connecting a ground wire from Studer to repro. Problem solved
How do you like the sound of the Repro with your Studer? I am using my Repro with my Otari and really like the sound. I am going to mod my Studer so I can have it both ways.

Jay
 

audioblazer

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while waiting for my Repro which took awhile to get it right, I received my studer a810 modified to use with Repro and I played tapeproject tape with the stock electronic. It certainly doesn't excite me as much playing it with Repro. Only issue is that I felt the gain is too high resulting in very low volume hum and on very quite track can be irritating. However with Repro I find the rendition of music so real, its pure pleasure to my heart. To me tapeproject is low entry cost to much better listening pleasure compared to vinyl . I have a reasonably good record set up , Raven AC 3 with Schroeder 2fw and ortofon A90 and Raven 10.5 with zyx omega gold with Tron reference with silver transformer and wires and at least 1000+ of original LPs. One thing that sucks about reel to reel is the lack of tape. Currently have only about 16 15 ips and would have been great to have at least 100+ 15ips tapes. Anyway, based on what I have read and understand, I would strongly encourage that u audition cello/king and change your tape head to Nortronic.
 
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audioblazer

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Jay, by the way who is doing your modding?
 

Doc B.

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Aug 31, 2010
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I've heard more than one comment that the tube repros are noisy. Myles, were you able to get that "under control". The K/C is very quiet - at least in the 50dB gain position. It starts to become apparent at 60dB of gain but I know of only one customer who is using that gain level - for MC phono.

Charles

Gain of the Tube Repro from the single ended output is 50dB. Gain from the balanced output is 65dB max and this is easily trimmed down to 60dB or 50dB or whatever. We typically measure a S/N of around 65dB. That is below the hiss level of most tape formulas. 1/F noise from the tubes is the noise source, and thus trying different tubes can change the noise floor. EF86 type tubes are well known in the microphone community for their great sonics in classic models by Neumann and AKG, and thus super quiet versions have been well documented by members of that community and tend to go for premium prices. I will suggest checking out my friend Klaus Heyne's microphone forum for more info.

Speaking of the (presumably unauthorized) Cello copy one of my business associates informed me a couple of weeks ago that no matter what he tried he couldn't trim a 6dB peak at 20KHz out of one running with a high quality 200mH head on an ATR 100, and he had the same problem with rising response at the bottom end - whereas the Repro response was flat from 30Hz to 20KHz with the same head on the same machine. I've also seen flat response from the Repro with Studer heads, requiring only a minor bit of head damping adjustment for some models.
 

Doc B.

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The Repro has single ended RCA outputs that come directly off of the second stage and XLRs at the balanced transformer coupled outputs (the third stage). In its current iteration the Tube Repro inputs can be set up with either RCAs or XLRs according to customer preference. We use the Neutrik jacks that allow either type of connector to be installed in the same chassis hole.
 

Steve Williams

Site Founder, Site Owner, Administrator
So Dan if I understand it is "either SE or XLR in (not both)

Pardon my ignorance but can you explain why SE comes off 2nd stage and the XLR off the 3rd. I am sure their is a reason for this which I am sure everyone would also Like to know.

Is their a sonic difference in your opinion between the SE and XLR. Is it measurable.

Dan, is it my imagination but........for those of us who use tubes it seems that going SE in and out is much quieter
 

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