ENBEE ZX1 and ENBEE ZX80: Hi-fi made in India

29 Replies

Gallery Reviews

 

The thing I really love about this hobby is that sometimes you can have a surprising new-gear-happy moment. This is the moment that happens when I get new gear, turn it on and I’m amazed by how good it sounds. To me, this is one of the best things in this hobby. I want to play all my favorite albums to hear how they sound on my new treasure. Even better if the unit is a complete gamble, not something many people know and recommend. It does not happen often – few pieces I’ve experienced it with before were my first vintage Marantz receiver – Marantz Model 2230B (big step up from what I’d used before), Exposure Super XX amp, Sonab R3000 receiver, Korvet 50U-068 S amp, Onkyo C-S5VL CD/SACD player, Bonsai speakers.

 

And recently with pre and power amp set, Enbee ZX1 and Enbee ZX80.

 

I was browsing our local auction site and spotted a name that did not ring any bells. At all. Now, that’s rare. It was a pre/power amp combo, with a price that was barely within my “experimenting” budget. I figured, about 135 dollars for a pre/power amp combo would be OK. No further info, no specs, just a vague reference to a minor problem with the preamp. Few bad photos, but what I could see kept me interested.

 

I hit google and found some info about the manufacturer and about audio gear in India. Audio gear was basically not imported to India until the late 1990s due to high customs duty on electronics. So they simply had to make it themselves, including higher end gear. Local brands that made these things had enough customers to flourish. Enbee was based in Delhi and run by a Mr. YM Nishi Nakra who’d been making audio gear (radios, speakers and amps) since the early 1950s. Mr. Nakra was making audio gear until 2005 or so, when he shut down his business due to old age and continued to provide service for his products at home. He was in mid-80s at the time. The units I have were manufactured from the early 1990s, apparently until mid-2000s. This means that they were designed and made by a guy in his 70s. All units were hand assembled. The brand had a cult following in India, supplied gear to recording studios and was praised for a very natural sound presentation. Enbee units are still recommended on local hi-fi websites and appear to hold their value – used set of Enbee ZX1 + ZX80 sells for it’s original retail price or more.

 

So, not 5 minutes later, I was on the phone with the seller, inquired about the problem with the preamp (hum with EQ controls on, fine with the controls off, and they can be switched off), I bargained a bit, because why not, got the price down 20% and bought the set.

 

2 days later, the Enbee separates arrived. I turned the power amp on, measured DC on speaker terminals (6 mV on one channel, 10 mV on the other, nice!). I fed a source to the power amp and checked it with headphones first, just to be sure. Good sound, no apparent problems.

 

The system I had on at this moment was an Inkel pre/power amp (similar power, mos fet, same as Sherwood CP-6040S/CP-6020S). So I first tried the ENBEE power amp with the Inkel preamp. I liked it! Not as much bass as with the Inkel power amp, but not bass-shy either, a bit cleaner, fast, detailed, pleasant, and pushed my Quadral Aurum 5 towers without any effort. I later tried this set with Quadral Amun MKV speakers, which are more difficult to drive than the Aurums, and the results were great. Deep and clear bass, pleasant midrange, clear highs and wide soundstage.

 

I checked the pre with headphones first – I do that to spot any problems with pre amps before they have a chance to play tricks on power amp and my speakers, I plug headphones to pre amp output sockets via an adapter. There was indeed some hum when I turned on and adjusted EQ controls, but with EQ off, and even with EQ on but flat, the pre amp worked perfectly. So I put it in the system.

 

The sound is very, very good. Lively, engaging, dynamic, but not aggressive. Vocals sound natural, details are nicely emphasized, and overall it sounds very well-balanced and fun at the same time. And that’s a real achievement in my book.

 

I’ve had two bad moments with this system. When I first listened to both power and pre, it sounded a bit gritty (particularly vocals). I was powering the power amp from a power strip and the pre from a socket in the power amp. After I plugged the pre directly into the power strip – no more gritty sound.

 

The other was when I decided to listen an LP. I put on a record and simply hated the sound: it was squeaky, lacked bass, basically crap. I tried to run my TT through an external phono pre to line level input to exclude problems with the TT, record, cables – no, it sounded OK. Then I noticed that the switch for MM/MC carts was depressed to MC position. I must have accidentally pushed it. I switched it back to MM and voila! perfect sound. Phono stage in this pre amp is really good by the way.

 

So, the only things left were a bit of cleaning and getting rid of the EQ controls bug. I will probably never use them anyway, but I wanted them to work all the same. Luckily it turned out to be quite simple. One of the 741 op-amps on the right channel EQ board was bad. Replaced, and no more hum! Due to these op-amps the EQ circuit has a fairly high noise floor (compared to the pre amp’s overall performance), but that’s not a big issue, and it can be completely bypassed.

 

Internally the units are reasonably well built, for an artisan product. Particular stages of pre and power amp are on separate boards (each stage in each channel has its separate board), which makes servicing easier. Power transformer is huge, output transistors are good old 2N3055s on an external heat sink. My only complaints are plastic knobs and buttons, and internally the slightly noisy EQ and it’s location after the volume pot. If the EQ circuits were before the volume pot it could attenuate the noise from the circuits. Maybe I’ll modify the pre amp at some point, but I’m in no rush – the noise is minor and I don’t use the EQ anyway. The things I could try if I decide to do that is ether move the volume pot downstream, so that it’s after the EQ boards, or replace the 741 op-amps, which are known for being noisy, with low-noise substitutes like TL071CP, or both.

 

If you can find these units in a good shape under 200 euros, I highly recommend them. Unfortunately the chances of that are slim – not many can be found outside India.

 

 

Technical information:

 

ENBEE ZX1 control amplifier:

 

Rated output – 0.775 volts,

Max Drive Capability – 10 volts,

Frequence Response – CD, Tape, Tuner, Aux-10 Hz to 80 KHz +/- 0.01 dB,

THD – 0.001 % 20 Hz to 20 KHz,

IMD – 0.01%,

S/N Ratio – >96dB

9 band per channel equalizer controls (switchable)

Built-in Phono Stage (MM & MC)

 

ENBEE ZX80 power amplifier:

 

Nominal power – 80 Watts per channel at 8 Ohms

Frequence Response at 1 Watt – 10 Hz to 80 KHz +/- 0.2 dB,

Power Response – 80 Watts per channel at 8 Ohms- +0-0dB-20 Hz to 20 KHz,

IMD for any combination of frequencies for instantaneous peak power of 200 watts or less – <0.1%,

Distortion at 1 Khz – 0.01%.

 

29 comments

  1. Value Badola

    Hello Sir,
    Greetings from India. I own the same combination of pre and power amp.I wanted to know of a way to effectively run 6ohms speakers with this setup. The “SENTINEL” speakers, which came along with the setup are put in series and are 8ohms. I, along with a friend, changed them to parallel. The sound has opened up. The highs are a lot more airy and bass tighter. But the speakers distort and go squeaky on highs if played even with the volume at 10 p.m.. is there a way to set this problem right?
    Thanking you
    Varun

  2. rafal lisinski Post author

    Hello,

    Welcome to Audio Room, good to meet another owner of this fine set!

    Unfortunately I do not know the Sentinel speakers, I have only seen one photo of them. I understand that the Sentinels are 2 way speakers with one woofer and two tweeters. I’m guessing you changed internal connection of drivers inside the speaker (maybe tweeters were originally in series and you changed that to parallel?), and that changed the speaker’s nominal impedance from 8 to 6 ohms?

    I do know that Enbee ZX80 drives 6 ohm and 4 ohm speakers without any problems, also at high volume. I used Enbee with both types. I do not think the amp is the problem in your case.

    I’m afraid your problem might result either impedance dropping much lower than the nominal value at higher volume levels, or from pushing too much power through the tweeters in the current parallel connection. If you have a power meter, you could try connecting it before one of the tweeters and see how much power it receives at the same volume level setting when connected in series and then in parallel. Without being able to test it, I would advise against using these speakers in their current connection. If you’re pushing more power than you should through the tweeters, the will be more audible at low volume, but will get squeeky and distort at high volume, and eventually you will damage them. Maybe try experimenting with different tweeters instead? Peerless drivers are very efficient.

    Kind regards,

    Rafal

    1. Value Badola

      Thank you so much for the reply. Yes the tweeters have been put in parallel. The original X overs have been changed too. When I run the pair with my PULZ RB250, the sound does not get squeaky. Though the highs have opened up beautifully I must confess. As I mentioned, I have 2 pairs of these speakers. The preamp has the provision for 2 power amps. So I have connected two amps to it. The speaker have 2 seven inch drivers and 4 tweeter in one setup. My friend suggested that we take 4 tweeters out and instead put 2 silk dome tweeters. This would take the added workload off the tweeters too (the tweeters being full range, basically paper cones which operate like that). I understand that this would increase the impedance and mellow the HIGHS too. You think this would be a good solution?
      Thanks
      Varun Badola

  3. rafal lisinski Post author

    Yes, that’s what I would try to do. Best if you use tweeters with higher power rating than the original paper tweeters, and use something that can handle fairly low crossover frequency. If the original tweeters are fullrange paper drivers, they might start quite low. If there’s still too much power going to tweeters, maybe try an L-pad? I can’t be more specific without knowing exact specifications of Sentinel and their drivers/crossover.

    1. Value Badola

      Yes I intend using Peerless drivers. My complete setup is of Indian make. Well… They are Indian too now. But I need to find silk domes with an impedance of 8 ohms right? If the drivers are 4 ohms and I have to put them in series so that the nominal impedance does not go down too low? But will that defeat the whole purpose as in series the twitters will produce lower sound?

  4. rafal lisinski Post author

    If you put tweeters in series, their impedance will add: two 8 ohm tweeters connected in series will have a nominal impedance of 16 ohms. If you put them in parallel, impedance drops: two 8 ohm tweeters connected in parallel will have a nominal impedance of 4 ohms. And yes, if you connect them in series, they will produce lower volume. But it might still be enough, you’d have to try and see. Peerless tweeters are efficient and quite “aggressive”. I would try with a single Peerless tweeter, too.

    1. Value Badola

      Hello,
      had a few problems setting them right. The 2 way xover was changes to 3 way. Finally set the speakers to 8.2 ohms in series parallel and it works great now. Though you already know, but if anyone else would read this in future, GREAT SOUNDSTAGE. I am a sucker for old stuff but when the equipment is good to compete with the new ones, the joy is even more. Read your other posts in other forums. It seems you keep a lot of vintage stuff too. But thank you so much for the help.
      greetings from India
      Varun Badola

  5. rafal lisinski Post author

    Hello again,

    Glad to hear that you’ve managed to solve this! Did you use Peerless tweeters, or did you keep the originals, only in 3-way setup?
    I love vintage (and simply older) equipment too, some of it sounds really great and if you don’t care about facilities like remote control you can build an amazing system for relatively little money. I guess this Enbee doesn’t qualify as vintage yet, but it will soon.
    By the way, does your ZX1 pre also have background noise when the tone controls are on?
    Anyway, if you want to share a photo of your system, let us know. We will be happy to add it to our gallery.
    Greetings,

    Rafal

    1. Value Badola

      Yes I used peerless silk domes. I have 2 sets of speakers and decided to operate on one pair first. They have become 3 way now. As I mentioned earlier, the xover has been changed. The original design had a 2 way xover. The impedance rests at 8.2 ohms. Yes the preamp does give a miniscule buzz when the EQS are switched on. But that gets garbed in the sound of music. . Unfortunately they need to be used at times, specially with phono, if the mastering is not too great. Infact my amp catches radio signals too if i use a slightly longer speaker wire. I live in Mumbai and unfortunately the weather here is hot, humid, sultry and wet, hence not conducive for electronics. To maintain these vintage items does take a lot of doing here. But I would hang on to these forever. You had written about changing the opamps, did you experiment with that? I am due to visit my friend in a day or two to discuss the same. Though I hope I get the ones you mentioned here in India to start with. By the way, I know Mr. Nakra personally and have spent a lot of time with him on my visits to Delhi. He is a genius with radios.

      1. rafal lisinski Post author

        It’s the same with my EQ, the noise is there, but minor and not a problem when the music is on. I haven’t tried replacing the op-amps yet, maybe I’ll make it my winter project. In case you try first, let me know the results. I mentioned TL071CP because it’s commonly suggested as a substitute for 741 op-amp, and it is cheap and available, so you should get it without problems. There probably are other options, too. If you’re in contact with Mr. Nakra, maybe he has suggestions?

        I have not noticed any problems with radio interference, but the FM signal is not very strong in my area.

        1. Value Badola

          I am starting with switching the EQ and volume pod sequence. As it does not need any physical change and only a change in the circuit, it would be easily achieved. I think that should make a considerable difference. Changing the opamps is a lengthy process which requires time. Unfortunately we do not have winters in Mumbai so can’t designate a time for the project. But the EQ and vol. pod change is being made as I write to you. Let me see what difference it makes. I’ll keep you posted.

          1. rafal lisinski Post author

            Great, do let me know! If you can make a photo of new connection of the volume pot and EQ (if it’s visible at all), please send it to me too. Theoretically it should remove most of the background noise at low and mid volume (and EQ switching noise), but there’s always a risk that non-attenuated input signal from loud source can overload the EQ, so play a loud CD and listen for distortion during loud passages. Good luck!

    2. Value Badola

      And yes, i’ll post some good pictures soon. Looking at the ones you have put here, this setup could walk the ramp.

      1. Value Badola

        It made no difference at all. I guess changing from 741s to TL071CP might make a difference. But another thing to look out for is the leakage from a few components at times. This is something that I encountered myself. The preamp does make a noise when the EQs are switched on, but remains quiet thereafter. As it is I heard nothing when I switched it to CD mode, my only problem was phono stage, but that seems to have gone too. I think the volume pod and EQ switch would have mattered more had it been an integrated model, which would have meant others disturbances too, with the power amp in the same unit. But all in all Rafael, the noise hardly comes in the way of music, if all the leakages are tightened. My only problem is that I can’t experiment with the preamplifier for very long as this is the only preamp unit I have and hence the only way to listen to vinyls. Haha so the ball is in your court, with winters arriving soon.

        1. rafal lisinski Post author

          Thanks for the report! No difference is strange, theoretically if the volume pot is the last thing in the circuit, it should attenuate any background noise too. Well, we will see after I experiment with mine. I have EQ switching noise (quite loud 1st time I use the EQ switch after turning on the preamp, much better afterwards – this probably comes from the switch itself or a capacitor near the switch) and minor white noise in the background when the EQ is on – that’s from 741s.

          Also, some preamps, especially their phono stages but not only, pick up noise from power amp’s transformer when they are directly on top or below the power amp due to insufficient shielding. I have 2 preamps that do that, a Harman/Kardon and a small MBO, they have to have at least 10 cm distance from the power amp, if they are closer they start to hum. But I did not experienced this problem with ZX1.

          One more thing I wanted to ask you: when you look at photos of my pre and power amp, are there any differences between my set and yours? I’m interested primarily in output transistors, filtering capacitors etc. It looks like my units have original parts, but I would like to confirm that.

          1. Value Badola

            Yes, if they are all made in Holland then they are all genuine. That is what Mr. Nakra used. But I would corraborate with the fact that distance between the pre and power might make a difference. If I turn up the volume, there is a hmm in the system in the phono stage. Though it remains only in the phone stage. Not in CD or tape. There is a current in the body too, which I do not know how to irradicate. Though I must tell you that I used my Klipsch SUB with it with great results, which is a big audiophile NO NO, but fine. I think i’ll try the whole process again. Though I do not know, but if NAD and other amps do not have a hmm in the phono stage then this could be rectified too. Mr. Nakra would have known this problem for sure.

          2. Value Badola

            Rafael tell me, if you crank up the volume in phono stage, do you get slight hum at 12 o clock, which increases from there on? The hum and hiss in my system was way too loud, so I put a thin metal sheet over the phono circuit, though the hum has not completely gone, it has reduced for sure. Is there something that I could do to better the situation?
            thanks.

            (PS:- It”s been long since I heard from you.)

          3. rafal lisinski Post author

            I was on vacation, and recently I focused more on developing the Polish language version of Audio Room.
            I have not noticed particular hum from the Enbee’s phono stage, but I wouldn’t be surprised if it were there. I will check next time I use Enbee and let you know. Most amps have it, after all phono input has much more gain than line inputs, which also translates to amplifying the amp’s internal hum and noise, and any interference the phono stage or the turntable cart might pick up. I don’t know how you placed your power amp and preamp, if one is directly on top of the other putting some distance between them could help. It did work in another system in which I had this problem.
            Also, computers are a common source of hum, so if you have a computer connected in the same room, you can try do disconnect it from mains and see if there’s any change.

  6. Value Badola

    Hi,
    I tried keeping the pre and power apart but that did not help. The hum starts at 12 o clock. Though it does not really interfere with the sound. Tell me, have you tried putting a tube preamp with a solid state amp? Is there a change in sound? There is one Mr. Viren Bakshi here who makes tube setups by the name of LYRITA AUDIO. A very respected name in the field and popular in the audiophile circles. He suggested that the phono stage will improve vastly if this combination is used.

    1. rafal lisinski Post author

      I don’t think I’ve ever listened to this set with volume control set at 12 o’clock. The room I use Enbee in is simply not large enough for that level. In any case, slight phono stage hum in an amp at that level is quite normal, and like you said, it does not really interfere with listening to music.

      I have not tried a combination with tube pre. I am tempted sometimes, but I stick to solid state for now. I’m afraid tubes will be a Pandora’s box for me, so I try not to open it. But I think phono stage is the one part of the Enbee setup that could be improved, at least with some records and cartridges it would benefit from some more body/warmth, and tubes could provide that. I did use a different sounding external solid state phono stage connected to ZX1 line input with good results (it was a TEC TC760LC ), smoother and softer highs, more bass and fuller midrange.

      I looked at Mr. Viren Bakshi’s website, he makes a phono preamplifier. if you know someone who owns one, maybe you could borrow it and try? I think for tubes I would try a phono stage connected to Enbee ZX1 pre first, and not a full tube pre amp connected to ZX80 power amp. I do not feel the need to improve Enbee ZX1 line level inputs.

      1. Value Badola

        Hello,
        pandora’s box is just about the best way to put it. Even I feel that if I jump on to the tube band wagon, then finding the best quality tubes and from the most reliable company and so on would drive me nuts. It would take me far away from the reason which helps me pay for all the equipment I own. A phono tube pre is exactly what was on my mind too. Unfortunately borrowing one here in my city is out of question as LYRITA AUDIO has a very select market and all the references given to me by Mr. Bakshi, own integrated amps. Size of the equipment has also started to come into play now. The music rack is getting loftier and so is my wife’s frown. The tube preamp that LYRITA offers is pretty big in size. I was thinking of a few smaller options online but haven’t found anything worth while as yet. The fact that almost all the brands have contrasting reviews only adds to your confusion. India is still not open to hifi markets and companies like MARANTZ, ONKYO and DENON sell their lower rung products in heaps here. Any perticular external phono stage preamp that you would suggest?
        Regards
        Varun

  7. Shashi Menon

    Hi
    I am also from India, I have handled earlier amplifiers from ENBEE when i was in college (1979 thereabouts). Those days there were 2 models viz; EA-50B and the Touch- 200. There were also speakers available with these amps which were not that great, how ever the amplifiers were pieces of art. When matched with a 12 inch BOLTON and metal dome tweeters, the sound was out of the world. The EA-50 B was rated at 50 watts RMS per channel and The Touch -200 , 100 watts RMS per channel. 2N3055 with split supply in quasi complimentary, there was even a preset to adjust the DC offset in the amplifier output.
    The Touch 200 had a very neat piece of technology, the selector switches were replaced with relays, that operated on a finger touch. There were disc shaped electrodes on the facia for each of the switch functions. One could select the required function (input select, loudness etc) by touching the required disc with one finger tip and a reference disc with another finger tip.
    My friend was the retailer for ENBEE in Kochi, and he had met Nishi Nakara. From what I gather, Nishi Nakara catered to a very small section of Audiophiles and was known for his build quality and of course the sound. He apparently did not have an aggressive marketing policy to promote the products, and sold mostly by word of mouth. A pity since in his prime he was right up there.. along with another famous audio guru of indian descent.. amar bose.
    regards
    Shashi Menon

  8. Johnson Chacko

    I bought a EA 50B with associated speakers in 1978 and still have them. It has given me wonderful service all these years. Recently the right channel volume has started varying on its own. Could not figure out the reason. Need help.

    1. rafal lisinski Post author

      The EA 50B was an integrated amp, right? With amps from that period, the cause for such behaviour are very often oxidizing contacts in switches, potentiometers and possibly speaker relay. Especially if the balance between left and right channel is restored ad high volume level, dirty contacts are the main suspects. If that is the case, thorough cleaning should remedy the situation. We are planning to add a section on basic amp maintenance in the future, but for now there’s a very good guide here:

      http://audiokarma.org/forums/index.php?threads/the-idiots-guide-to-using-deoxit-revisited.207005/

      The basic idea is to spray the cleaning agent into each potentiometer and switch so that it reaches the contact inside, and then work each of them (press/flip switches and turn potentiometers many times) to wipe off the oxides and dirt. The cleaning agent mentioned in the above guide is DeOxit, which is available in the US, more difficult to find in Europe, not sure about other parts of the world. If you can’t find it, get a product that’s available in your area and is called something like “electrical contact cleaner”, “electrical switch cleaner”, “potentiometer cleaner”. DO NOT use products like WD40, you will destroy your amplifier.

      If cleaning potentiometers, switches and possibly speaker relay does not help, the cause could be some components, most likely capacitors in the preamp section (but it could be a transistor or resistor too), deteriorating due to age. The amp is almost 40 years old after all. The only solution in this case is to replace bad components, you will probably need an electronics technician services for that.

      If the problem only affects the PHONO input, the most likely problem is a bad component in the phono preamp. Again, bad component needs to be replaced.

      But first, check interconnect cables that connect sound sources to your amp. It could be as simple as bad cable.

      Hope that helps you a bit. By the way, I couldn’t find photos of EA 50B anywhere. If you could take a few photos and send it to me, I would be very interested to see what this amplifier looks like, and with your permission maybe post them on our website. you can email me at audioroom_rafal@wp.eu

      1. Johnson Chacko

        Thanks for the prompt reply and valuable inputs. I will try and get all that done. I am located in Pune, India.

        1. rafal lisinski Post author

          No problem. We’re in Warsaw, Poland, so unfortunately we won’t be able to physically assist you, only share some hints on how to tackle this issue.

  9. Johnson Chacko

    EA 50 B is an integrated amp. I am using a dvd player through the aux input. The interconnect cables are good and connections are firm. I will email the photos.

    1. rafal lisinski Post author

      I got your photos. I don’t see anything obviously suspicious, but any of these smaller blue capacitors could be bad at this point. In any case, the amp certainly does need cleaning, so definitely start with that. First remove as much dust and dirt as possible from the inside of the amp using a small paint brush, hair should not be too hard to avoid destroying connections. Be careful around the VRs – the four horseshoe shaped components that are on two circuit boards, best if you don’t touch them. They regulate voltages in the power amp, they shouldn’t be moved even slightly without measurement equipment properly connected.
      You can also blow dust out, but do not vacuum clean (too risky).

      I can see corrosion on metal parts, which means that contacts in pots and switches are certainly oxidized too. Once you removed dust and dirt from the amp, you should clean all switches (I can see that there are a lot of them) except the power switch and probably the switch on the rear panel (that’s a voltage selector right?) by spraying contact cleaning agent inside each switch, letting it stay there for e few minutes and then working (pressing or flopping) the switch many times. The potentiometers that I can see are slider type. If you clean them, best to use the cleaning solution called Fader Lube. If you don’t find that, use what you have, but in very small amounts.

      I checked, DeOxit is available in India on Ubuy, but it seems expensive. This thread lists a few alternatives you can find in India, they will probably be cheaper:

      https://www.techenclave.com/community/threads/searching-for-an-indian-electronic-contact-cleaner-like-deoxit.137213/

      There’s also something called Protochem Electrical Contact Cleaner, it’s much cheaper than DeOxit and should be OK too.
      Best if you find something with a long straw applicator, that it allow you to reach the switches located deeper witout having to dismantle you amp.

    2. rafal lisinski Post author

      Having looked at the photos, I see that the amp has PRE OUT jacks for connecting an external power amplifier. If you have or can borrow one (or powered speakers), you could connect it to your Enbee EA-50B and test the sound. If the problems with the right channel volume persist also with an external power amplifier or powered speakers, the problem with your Enbee is somewhere in its preamplifier section. If the problems with the right channel volume do not occur in this configuration, that would mean that the Enbee’s power amplifier section has issues. This would help search for bad components, if cleaning does not help.

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