Oops, I did it again, damn it!!

[Chivas]

Recently I've been tempted more and more by the dark side (valve) and have been contemplating a valve pre-amp.

This week I nonchalantly made an offer on ebay whilst totally pre-occupied with something else, went for a shower and when I came back saw that it was accepted. That sinking feeling!!

Anyway, tomorrow I'm driving south to pick up a pair of Icon Audio MB 845 http://www.iconaudio.co.uk/MB845.html monoblocs.

I really hope that they work well with my speakers!! I've never owned a valve amp (apart from my Pure sound phono stage which is plug & play), is there anything I should be aware of?

Current system is thus:
Technics 1210 with Timestep PS
OL Encounter arm with MM III
Pure sound p10 phono stage
CA 840C cdp
CA 840E pre
CA 840W now replaced by the IA 845 (if they work in my system)
Kef Reference 203/2

If they don't sound good, the seller has a 14 day return policy, but I got them for quite a good price and will offer 1st dabs to this forum, so let me know if you may be interested.

Ps. Yes I know, I did it the wrong way around and next step will probably be a new pre, thinking of the IA LA4, Croft or Ali gave me the name of a guy who builds custom amps.

Chivas

[Stratmangler]

You might find that the amps lose grip a bit on the lower frequencies - you'll need to suck it and see.

[Marco]

Possibly, but those are bloody good monoblocks... What's the spec on the Kefs, Retief? :)

Marco.

[Chivas]

Possibly, but those are bloody good monoblocks... What's the spec on the Kefs, Retief? :)

Marco.

Model Model 203/2
Design Bass reflex three-way floorstanding loudspeaker, magnetically shielded
Drive Units 2 x 165mm (6.5in.) LF, 1 x 165mm (6.5in.) Uni-Q MF including a 25mm (1in.) titanium HF
Crossover Frequencies 300Hz, 2.3kHz
Sensitivity (2.83V/1m) 89dB
Frequency Response (+/-3dB) 50Hz - 60kHz
Maximum Output 113dB
Input Impedance 8 Ohms (3.2 Ohms min)
Amplifier Requirements 50 - 200W
Magnetic Shielding Yes
Bass Extension 40Hz (-6dB)
Weight 26.5Kg (58.3lbs)
Dimensions (H x W x D) 1020 x 248 x 405 mm ( 40.2 x 9.8 x 15.9 in.)

[Audioman]

You should have no problems with these. IA 845 have long been Hi-Fi World favs. Very powerful and 89db speakers should be no problem. I didn't realise they still did the originals because the mk2 is huge even more power and quite expensive. Congratulations on buying these. You may have to upgrade your pre amp or maybe try a passive type though.

[camtwister]

is there anything I should be aware of?



Icon supply two manuals and a meter for biasing work and valve measurement, so you can ease into that side of things.
You may need some new furniture - have you thought about how to site them?
I'm excited and they're not even mine!

[AlexM]

DHTs like the 845s run very high voltages and external temperatures... hope you don't have pets!. Do the Icon Audio amps have some form of valve cage?.

I am very envious- they are a fabulous amplifier and I would expect that it will work well with your existing speakers. The CA pre-amp isn't at all shabby either, so be careful not to side-grade rather than upgrade!.

Good luck with them - I think you will be happy once the purchase price trauma is forgotten.

BR,

Alex

[Ali Tait]

845's do very good bass for valves, should be fine as long as the speakers are not too reactive a load.

[Chivas]

Hi guys, thanks for all the feedback, I'm starting to get excited now!!


Icon supply two manuals and a meter for biasing work and valve measurement, so you can ease into that side of things.


That's the problem, they come without the original packaging, manuals or testing equipment. They belonged to an elderly gentleman who passed away before he could use them, the valves were apparently unopened in their boxes, but the rest couldn't be found. So I'm bloody nervous to flick the switch after the transport back to London!! :deceased:



The CA pre-amp isn't at all shabby either, so be careful not to side-grade rather than upgrade!.

That's what I'm scared of. The thing is, I want as little as possible between these guys and the source, so if they drive my speakers easily enough, I may get away with a passive and could have some spare change after I've sold the CA on. My problem with the Croft is that I will be paying for a phono stage which I don't need - unless it is much better that the Pure sound, in which case I can sell that on too. If I carry on like this, these amps may even pay for themselves!! :eyebrows:




I'm excited and they're not even mine!



I think you will be happy once the purchase price trauma is forgotten.

I hope so!! I've been kicking myself all week, because this was definitely not in the financial plan, but hopefully once I see and hear them, the excitement will wipe all the guilt away!!

[Chivas]

Re the bass - the Kef's don't go too low (which is a good thing because my room won't be able to handle it) so I don't expect this to be a problem, as long as the amps can control them

[camtwister]

The very next thing I recommend is this:
http://store.acousticsounds.com/d/67246/Ella_Fitzgerald-Clap_Hands_Here_Comes_Charlie-45_RPM_Vinyl_Record

Then you should purchase one of these:
http://www.national-lottery.co.uk/player/p/lotterydrawgames/lotto.ftl

And then go here:
http://www.croftacoustics.co.uk/micro25_R.html

http://www.quad-hifi.co.uk/model.php?sector_id=1&range_id=1&model_id=2&content=3#details

Have a memorable weekend.

[Chivas]

The very next thing I recommend is this:
http://store.acousticsounds.com/d/67246/Ella_Fitzgerald-Clap_Hands_Here_Comes_Charlie-45_RPM_Vinyl_Record

Then you should purchase one of these:
http://www.national-lottery.co.uk/player/p/lotterydrawgames/lotto.ftl

And then go here:
http://www.croftacoustics.co.uk/micro25_R.html

http://www.quad-hifi.co.uk/model.php?sector_id=1&range_id=1&model_id=2&content=3#details

Have a memorable weekend.


I think I'm better off starting with http://www.national-lottery.co.uk/player/p/lotterydrawgames/lotto.ftl !!

Oh yes, how do I transport these babies? Should I remove the valves or keep them in?

Have a good weekend too, I'll post my impressions over the weekend!

Chivas

[AlexM]

Take the valves out before moving it, and put them back in their boxes. Record which valve came from which position, and put each one back in the socket it came from.

Not that they should suffer any shock damage while moving the amps, but better safe than sorry!. Use a clean cloth to avoid putting finger prints on them, or clean the glass carefully before firing it up - they get very hot, and finger grease will burn onto the glass once they are in use.

[Chivas]

Useful advice, I didn't know that, cheers Alex!

[AlexM]

p.s. never power up your amp without speaker cables and speakers properly and securely attached as the output transformers can be damaged.

Good luck, hope you enjoy them... let us have your first impressions when you are up and running.

p.p.s. get hold of a copy of the user manuals ASAP and familiarise yourself with the valve replacement and biasing procedures. I'd check that biasing is on the mark and stable over a period of time. valve amps need a little more tlc than solid state, so best to get comfortable with the procedure.

Alex

[Chivas]

p.s. never power up your amp without speaker cables and speakers properly and securely attached as the output transformers can be damaged.

Alex

Even more useful advice! As the first thing I was probably going to do was to power them up without the speakers connected, just to make sure in case something goes pop that my speakers aren't included in the show!!

I will call IA regarding the manuals, hopefully they're helpful, even though I bought these 2nd hand.

PS. I've never checked the valves in my Pure Sound phono stage either as I figured I would be able to hear when they go off colour and need a replacement. Just out of interest, what would be good relacement valves for the P10?

[AlexM]

I think that the valves in the P10 (6992 & 12AX7) will be cathode-biased (i.e. auto-biased), so no bias adjustment would be required. As you say, when the treble response starts to droop and dynamics go it is time to replace them, so let your ears be the guide.

I am assuming that the Icon Amp could be either auto-biased, or manually biased. For output valves it is very important for the bias point to be correctly adjusted. If the bias current is too high bad things can happen (red plates/thermal runaway/permanent valve damage). Actually the 845 won't red-plate as I think it uses graphite, but it won't sound good and the valves will have reduced service life.

Sorry for the non-specific guidance as I'm not familiar with the Icon 845. Some general info about valve amps can be found here (http://www.lenardaudio.com/education/14_valve_amps_2.html)

Cheers,
A.

[jandl100]

Ooo heck - I am seriously jealous! They look fab. 90wpc. Wow.
I've always fancied trying 845 valves, but it hasn't happened yet.

I'll be very interested in what you think of the sound. :) .. I bet they'll be fab.
Jealous Jealous. :stalks::eek:

[Jonboy]

p.s. never power up your amp without speaker cables and speakers properly and securely attached as the output transformers can be damaged.



Do you mean either connected or not connected and or just badly connected as i had better tell my mate he been servicing and fixing valve amps all wrong for the last 40 years or so with no speakers connected



Nice amps, i have a pair of 845 SE that probaly came from the same factory under a different name, 1200 or so volts your playing with now

[Chivas]

Wow!!!
They survived the trip back to London and they sound bloody marvellous! In short (and trying to avoid sounding like a hifi magazine), they add considerably more weight to the music, bass is much deeper and heavier, definitely brought a 3rd dimension to the soundstage and the notes have much more texture. The sound is "velvety" and extremely addictive, whilst retaining all the detail!

I'm over the moon! Thanks for all the advice and feedback! I'm travelling for work at the moment, but will post pictures as soon as I get back.

Now for the next issue! I don't have space to put them - I doubt they will go into my equipment rack and I may have to move them a considerable distance. So the question is: what is preferable, long speaker cables or long interconnects? If I move them to the speakers, I will have to use IC's of up to 10m!

[AlexM]

I would always prefer longer speaker cables and short interconnects (unless balanced), within reason. these definitely need plenty of space vertically on a rack - they would probably set fire to my rack!.

speak to Icon audio support about placement guidelines, and get a copy of the manual while you're at it..

Regards,
Alex