Preamp and amp recommendation (BD-Design)
by putterart 
, Friday, August 17, 2007, 23:46 (6096 days ago)
I am new to horns and this forum. I purchased used Oris 150s with Lowther PM4A aer modified drivers. I am using Avantgarde 225 subs. I have tried various push-pull amps. What do others recommend as preamp/amp? Also, what speaker wire do others use? Thanks for the help.
Preamp and amp recommendation
by madprofessor 
, 27777 Ganderkesee, Germany, Saturday, August 18, 2007, 09:53 (6095 days ago) @ putterart
Hallo!
I also use a horn-system. For speaker-cables I´ve got good results with van den Hul Revelation.
To drive the horns, I use a Single Ended Valve amp - for testing a modified Music Angel with 845 output tubes, but I´ m building now an own amp using the GM 70 triodes.
The preamp I build myself, using very good components, but very few active elements. All the other cables I also build myself.
It´s always difficult to give recommendations of production gear - a lot of stuff is to expensive for the performance offered.
Maybe a Hiraga would be a good choice for power-amp - they are not to expensive used. Or a decent valve amp.
I didn´t hear Berts new amps, but what I read in the Forum sounds very promising.
Best regards
Stephan
Preamp and amp recommendation
by Bert , Sunday, August 19, 2007, 12:10 (6094 days ago) @ putterart
I am new to horns and this forum. I purchased used Oris 150s with Lowther
PM4A aer modified drivers. I am using Avantgarde 225 subs. I have tried
various push-pull amps. What do others recommend as preamp/amp? Also,
what speaker wire do others use? Thanks for the help.
It depends what you are looking for and what is most important....
Do you want accuracy or good sound?
What you hear is the whole chain, from the source through the chain ending with the room wherein you are listening.
I have heard good systems with push-pull amps, with SET and solid state.
What type of music do you listen to mainly?
Bert
--
BD-Design - Only the Best!
Preamp and amp recommendation
by madprofessor , 27777 Ganderkesee, Germany, Sunday, August 19, 2007, 15:23 (6094 days ago) @ Bert
Hallo Bert!
Of course You are right, that always the complete chain and the room cause the final result. Some money spent on the room can give much better results, as the same money spent on equipment.
Also I agree, that different kinds of amps can give very good results. But to my experience, single ended triode amps have something special - more of the feeling to enjoy the music more "live". By a technical point of view, valve amps never perform as good as solid state-amps, which shows that the way, amps are normally measured, doesn´t take grip on all facts. I´m trying to find some of that substantial, but till now no standard procedure, measurements.
For example: I measured the output of a good D/A- converter up to 200 MHz. There were a lot of spurious signals, like clock and mixing products. Constructing a filter, damping this unwanted signals by about 80 dB, also the audible sound improved quite a bit.
There are still many ways to explore!
Best regards
Stephan
Preamp and amp recommendation
by putterart , Monday, August 20, 2007, 17:28 (6093 days ago) @ Bert
Thanks all for your kind reply. I am looking for good synergy and thus good music. I have an excellent front ends on both the vinyl and digital. I listen to jazz, classical, female pop vocalists,and folk. Accuracy is not my top priority, but I do like a low noise floor. I have a room that is 17 ft by 30 feet, but I set up the horns so that they fire the length of the room and basically can go back up to 24 feet away.
I have a pair of refurbished Quad 57s and I have tried all my push-pull amps on the Lowther- Heathkit UA-2, Tektron, Music Reference RM10 MK2, Dynaco ST35. The Lowther PM4as are 15 ohms. I thoroughly enjoy what the Quads offer, and the horns provide a different presentation- more a live presentation.
I was hopeful to get some guidance on what other forum members have tried. The fellow who I purchased the Oris 150/Lowther PM4a used a Yamamoto 2a3 amp. I have read that that the PM4As like power, so I was uncertain how many watts that I would actually need. I have never tried a SET amp.
Preamp and amp recommendation
by Bert , Tuesday, August 21, 2007, 07:51 (6092 days ago) @ putterart
I have read that that the PM4As like power, so I was uncertain how
many watts that I would actually need. I have never tried a SET amp.
A quality SET amp (with good power supply and OT's!) delivers enough power and headroom for the Oris horns. I can't name any specific brands but the Lady Days I have been using (Mesh Plate 300B's) did do a very nice job (low noise floor, enough headroom and enough gain to be able to use a passive TVC pre).
Bert
--
BD-Design - Only the Best!
Preamp and amp recommendation
Dear Bert.
I am in a process of buying a pair of Oris horns.
I have Audio Note Conquest today (and some other amps-a pair of Quad IIs also) preamp is AN M3.
But I am also considering this OTL design.
http://www.transcendentsound.com/singleended.htm
Has anyone experience with it combined with horns?
Best Regards
Odd Magnus
Preamp and amp recommendation
by Bert , Tuesday, August 21, 2007, 08:25 (6092 days ago) @ bambadoo
Dear Odd,
But I am also considering this OTL design. http://www.transcendentsound.com/singleended.htm
Has anyone experience with it combined with horns?
I have only heard good things of those OTL's in combination with the Oris horns. Never heard it myself though...
Bert
--
BD-Design - Only the Best!
Preamp and amp recommendation
by robmatthew , Wednesday, August 22, 2007, 17:15 (6091 days ago) @ Bert
I have tried quite a few amps with the ORIS 150.PM4a combination and have concluded the following:
1) The Lowther drivers can handle some power but I would not go above 25-30 watts for the sake of driver safety in case of an accident.
2) The system works fine with 8 watts or more. Less than that I feel hampers dynamics although they still will play very loud with a couple of watts.
3) I had the Transcendent OTL amp and it was very sweet and smooth but lacked the dynamic impact that is so wonderfull with the ORIS horn.
4) Personally, I am afraid to use transistor amps with these drivers because a shorted outpput transistor can send the output voltage to the rail and blow your driver in a split second even with a rail fuse - that happened to a friend of mine with Fostex drivers. At least Lowther makes it relatively simple to replace a blown diaphragm assembly. I caNot speak for Bert's amp, though. I'm sure he feels secure in using it for his products and the folks think it is great. I would try it if I did not already have a shelf full of amps.
5) That brings me to my final conclusion (apology for the length of this post). As sensitive as the ORIS/Lowther is, it really opens up with 20 to 30 watts even though it only needs a fracton of a watt most of time. It is not that you need to play it so loud, it just sounds easier and more dynamic with the the added power reserve BUT, it has to be "good" added power reserve and that is never cheap.
Bob Figlio
Preamp and amp recommendation
by putterart , Thursday, August 23, 2007, 22:03 (6090 days ago) @ robmatthew
My PM4a's are 15 ohm. So if I use an amp with an 8 ohm amp rated at 16 watts, the effective wattage is approximately half? Of the amp/preamp combinations that you tried, which combination provided the lower noise floor musicality? Did you find that a valve was better than a SET?
Preamp and amp recommendation
by robmatthew , Saturday, August 25, 2007, 02:56 (6088 days ago) @ putterart
Question:
Of the amp/preamp combinations that you tried, which combination provided the lower noise floor musicality? Did you find that a valve was better than a SET?
I have been using a variety of amps from SE 811-3 with Electra-print silver transformers, 300B and 2A3 with the silver Electra-prints,and Kt88 SE with James transformers. Right now I am using Fountek EL34 modified PP amps and like them very much.
Let me tell you something, though. Years ago I read about this crazy guy who built these huge bass horns in his house and I was intrigued by his dedication, stamina (energy) and downright courage to do such a thing in a family environment, of course it was BD. There was also another nut in the US called Burwen , I believe, who built his house on a bass horn. Whatever, after many years of trying, building and experimenting (I am now very old even by my own calculation) I have come to the conclusion that a couple of people have it right. Bert is one of them. The other guy runs Supravox. I have both systems and am completely involved with both - one horn loaded, the other, open baffle.
The point is, if Bert says it's good, it's good. period. I usually only trust my own ears. But Bert's systems converted me from "all horns are colored" to owning a double 150 system. I am sorry I did not buy it from Bert, but I am in the US and they became available. Now that the US is a "third world" nation thanks to the present administration, I have to count my pennies.
In short, IMHO. you can spend a lot of money trying to save money or just buy what Bert suggests (I never met him and I get no commission) and go with it.
You could build your own stuff for years, which I have done. That has its own rewards. Or you can simply go with what works and save a lot of time and money.
I hope I did not overstep the bounds here, bit I really feel that Bert has done so much ground work that his opinion is very valuable.
Bob Figlio
Preamp and amp recommendation
Bob, I totally agree with you on this. I tried for many years to get the best out of Lowthers using SET amps like the Audionote Meishu. Things were sweet but I was never 100% convinced of clarity or dynamics. I guess I hung on in there as everyone else was claiming this was an ideal combination.
A switch to an EAR 861 was a revelation. It was the classic lifting of heavy curtains in front of the performance, and dynamics to die for.
The amp gives about 35 watts and is perfect for use with a passive transformer volume controls.
![[image]](http://www.ear-usa.com/images/861n.jpg)
Preamp and amp recommendation
by Bert , Friday, August 24, 2007, 13:14 (6089 days ago) @ robmatthew
Hi Bob,
5) That brings me to my final conclusion (apology for the length of this
post). As sensitive as the ORIS/Lowther is, it really opens up with 20 to
30 watts even though it only needs a fracton of a watt most of time. It is
not that you need to play it so loud, it just sounds easier and more
dynamic with the the added power reserve BUT, it has to be "good" added
power reserve and that is never cheap.
Thanks for the elobaration and it does match with my own experiences. With one Watt things do play loud but the "drive" is less than with higher powered amplifiers. Although, there are 6Watt amps that do provide the drive but these have highly overdimensioned OT's and power supplies. This way the first Watt is a real Watt with much headroom behind it.
Bert
--
BD-Design - Only the Best!
Preamp and amp recommendation
by werner , Friday, August 24, 2007, 16:17 (6089 days ago) @ Bert
Bert,
Does this also count for the AER BD1 drivers I use ?
I'm playing with homemade amps using 2A3 tubes and amorph output transformers.
They wil not produce much more than 3 watts. I am very happy with the sound but
should it sound better/different with let's say 8 watts from 300B tubes or the 30 from crazyA ??
Werner
Preamp and amp recommendation
by Bert , Friday, August 24, 2007, 16:44 (6089 days ago) @ werner
Bert,
Does this also count for the AER BD1 drivers I use ?
Yes, all full drivers gain drive with more power (or plenty overhead)
should it sound better/different with let's say 8 watts from 300B tubes or
the 30 from crazyA ??
Define better... :wink:
3W versus 8W is hardly noticable in terms of power. A tube versus the CrazyA is another thing where the CrazyA will give you all the drive but will also show anything without adding its own signature.
Bert
--
BD-Design - Only the Best!
Preamp and amp recommendation
by PeterSt. , Netherlands, Friday, August 24, 2007, 17:06 (6089 days ago) @ Bert
Define better... :wink:
Bert, may I ?
Easy : more 1:1 "translated".
Maybe you are too shy on the CrazyA Bert. Also, I may be the only one having the CrazyA (in double stereo version, each with mid/high and bass section), and I can tell that I hear nothing of colouring whatsoever.
Also, people should not forget that the headroom of horsepower is good for music quality.
IMHO "better" must always be about untranslated sound. Not adding colour you like; if you need colour, something else is wrong. 
My 2c,
Peter
Preamp and amp recommendation
Bert,
Does this also count for the AER BD1 drivers I use ?
Yes, all full drivers gain drive with more power (or plenty overhead)Bert
How about the Orpheans, does this apply to them too?
Frode
Preamp and amp recommendation
by Bert , Sunday, August 26, 2007, 15:36 (6087 days ago) @ Frode
Hi Frode,
How about the Orpheans, does this apply to them too?
I did not switched much between amp principles much but so far it is less an issue regarding drive and control. The main difference will be the tonal balance as most tube amplifiers do not like to see any impedance changes which will change the tonal balance of the system.
Bert
--
BD-Design - Only the Best!