Problems getting the best out of my Berning

Hello All,

Thanks for your suggestions! I’ll try to provide answers, and then highlight the remaining questions that arise from consideral all the responses:

1. As for the preamp – I’ve run it with and without a Rogue 66. In both cases, I still get the same undesirable tonal balance.

2. As for digital sources, I don’t think that is the problem, because I use the same sources through the other (pre-Berning) setups without ever having these problems.

3. As for impedance matching with the speakers: I’ve tried this with three different speakers (Triangle Titus, Dynaudio Audience 72 and Proac 2.5’s), and relative to the pre-existing amps on each speaker type, this same issue has arisen.

4. I have tried the three feedback settings. I get the best bass response, and an overall more controlled sound on the normal setting. I like the normal and the middle setting. The low setting is too “loose” for me, I perceive a slight distortion to the sound (maybe due to less driver control).

5. As for the tonal balance, I am pleased enough with the high end. A drummer friend of mine noticed that the cymbals and high-hat seemed a bit removed. We both thought that this is due to the psychoacoustics of the prominent midrange.

6. The amp is located at least 8” away from anything with steel in it. Sometimes on the carpet, other times on a wooden platform on the carpet, other times on a wooden bureau.

7. What about break-in time? How many of you who have purchased the ZH270 new had to break in? I take it few had similar problems as me? Anybody know how much break-in is required?

8. I will test all the tubes. I guess I’ll need a tube tester, or maybe one of the (few) electronics shops in town (Flagstaff) has one. There are many for sale on ebay – any suggestions on how to choose? How much would a decent one cost? Anybody wanna lend me one if I cover shipping (only half kidding!).

9. It sounds like changing tubes isn’t going to be the key for tonal balance, and I should start with cables. Any suggestions for good neutral sounding cables to try? The Proac’s are biwirable, and I would likely go that route (Ian, is that what you are doing?). I don’t have a tremendously unlimited budget. So far, recommended cables include: Cardas IC’s ($$$),TG Audio HSRs, Analysis Plus Oval 9’s, and Luminous Tech Syn Sig. Any other suggestions, with a total cable update cost of maybe $500 (IC’s and speaker cables) would be very much appreciated. Which Cardas to go for? Should I not biwire for now, to save money initially?

10. If I do make a tube change, it sounds like I should change the input tubes first (12AT7's) to see what happens. Or should I change the entire tube compliment at once. Again, I’m trying to be cost conservative. It was already a huge enough stretch to purchase the amp.

Thanks again for everyone’s input and concern. This excellent amp must meet its potential! Please keep sharing your suggestions and ideas.

The amp only has about 10 hours on it total. The other CDP I'm using with it is an Arcam FMJ CD23.

Tubegroover - would you go for the Cryo'd tubes first? Or do the NOS first? Thanks.

I'm thinking I should ship it back to David. The shipping wouldn't be costly for such a light amp (insurance could be >> the shipping cost), and he would be most qualified to test the amp thoroughly (including the tubes). Perhaps that would be the best first step. He mentioned on the phone that he listens to all newly built amps for several days, but perhaps this was not apparent.

October 10th Update!

Hello to all you helpful Berning owners! Well, it's been a couple of weeks and here is what I have to report.

1) I took the unit to an electronics expert person who just happens to live in Flagstaff (used to work at UC Santa Barbara), and he took it through some bench testing. The results were interesting, much of which above me. But the tubes were working fine.

2) I have kept the amp on for over 100 hours, and the break-in has improved the bass response to that of (or near that of) my other amps: Pass Aleph 3 and ARC VT100-mk2. Still dominant in the midrange though, and a bit fatiguing.

3) Alan B (see posts above) lent me a quad of Cryo'd Sylvania output tubes, and I popped them in and listened today. There was a significant improvement. The bass got more detailed and stronger. Overall detail increased, openess increased, and soundstage improved. Despite a ground problem with my Rogue 66 preamp, the noise floor still seemed way, way down there! Listening to Nora Jone's "Come Away With Me", the cymbal brushes lost a bit of excess metalic nature and became more "brushy". There was a reduction of the midrange emphasis, but it is still a bit there to my perception. Now at the point where I could see adjusting to it, as a different sound approach.

4) I'm away for four days vacation, but when I get back, I will be doing more listening comparisons between the amps. A quick impression now: while the Pass sounds flatter than the Berning, the Berning sounds clearer (e.g. clearer vocals and kick drum). Anyhow, I'll also be working with system synergy. Newly arriving are a pair of Cardas Neutral reference biwire speaker cables, two Neutral Reference interconnects, a Golden Cross interconnect, and some Harmonic Tech interconnects. All are on loan in order to work with the synergy. I will keep y'all informed.

5) I'm really wondering whether I should be trying different input tubes, while I'm trying to make this decision. Any advise? Where to get them...

Thanks All. Peter

I am very happy with the Proac-Aleph 3 combo, but I would not say that the Proacs are very warm or laid back, atleast with my current cabling and the Aleph amp. Instead I feel that they are very forward and accurate. I've mentioned that before on Agon, and it was suggested that the perception of Proacs being warm and laid back may be due to the fact that most people use tubes with them. Anyhow, the perception of exaggerated midrange occurs with all the speakers I'm using - triangle titus, dynaudio audience 72 (both soon to be replaced). I really do like the Proacs, though I also look forward to listening to others at the CES in January (including the Ref 3).

Rhirsch and Ian - what can you say about the synergy between the Proacs and the Berning? The overall sound? Rhirsch - what type of cabling do you recommend?

By the way - the current strategy is to perform atleast 4 days of continuous burn in, have the tubes checked, and then assess the situation again. If it doesn't improve, I'll send the amp to David for a check up.

Yikes! I don't think I can afford the TG Audio Lab cables. Got any other suggestions for someting neutral that would be an asset? For speaker cables I currently have Audioquest Type 4, slates, and MIT Terminator 2's available. Of course, I'll do tube checks and break-in first, and maybe even tubes.

Since the cryo'd NOS output tubes created an audible improvement, I decided to go ahead and do the entire tube compliment replacement. From Brendon at Tube World, I got the input compliment that Tubegroover recommended:

12AT7's Brimar Black Plates NOS and 5965's GE "5 Star"

A QUESTION: Brendan sent me two matched pairs of Brimars. How should I arrange them in the amplifier - vertically (pair per side) or horizontally?

Allan will be sending me a new set of Cryo'd tubes shortly.

Thanks Kriskosiba, I am keeping the amp away from steel things, atleast a foot if not more.