Dmannnnn

What were your impressions, as far as differences between the two tubes? This is still a Paramount that is being switched back and forth, correct? I am contemplating switching myself.

Did you make the switch? How did it turn out?

I experimented with this a little bit, just a passive setup using the modded RF-7 crossover. The results were as expected, much better bass response than with 300b's alone, but it just seemed like a waste of beautiful tube power with the crossover point so high (2200hz). You just loose too much of that tube midrange. If I had an active crossover I might try it again, but I don't think it's safe to run the horn much lower than it already is. Does anyone know how low the RF7's HF driver can safely go?

Saw this posted on another forum and thought I'd share.

I will go out on a limb here and recommend something. One of this type/line from this manufacturer. http://cgi.ebay.com/Vintage-Harman-Kardon-HK-560-Stereo-DC-Amplifier_W0QQitemZ260505333723QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item3ca753efdb I bought a similar one for $40 on the same site awhile back, and I can say it was the best value purchase in audio I have ever made. Very sweet sounding receivers that can be had for a song. These pair very well with klipsch products. Give it a try (not necessarily this one, it is just for illustrative purposes) if it's not right for you, it won't cost you much. If the link stops working: It's an early 80's Harman Kardon HK series receiver.

Since you are a DIY'er you should definetely try it both ways. I'm not familiar with the S.E.X amp, but on the paramounts I just had to swap a couple of connections on the output transformers. I wonder if anyone here has an impedance curve for the RF-5's. On my 7's the improvement was not small. It really improved the bass response even with a less than optimal room placement. Low power tubes may not be the absolute best match for the reference series, but my system sounds better than ever. The DIY thing can be an addiction. Before long you'll be building your own awesome 24 step attenuator and upgrading capcitors in the amps and speakers. If you're not careful you'll end up making custom interconnect cables. I've become the kind of person who would pay more for the kit than the finished product. [:$] I still find it hard to believe that I actually built something that sounds so damn sweet.

Have you gotten the speakers? Let us know how you like them. If you built the S.E.X with 8 ohm outputs, I would suggest listening to them in this configuration at least a week so you can get a good impression of the sound. Then wire them for 4 ohms. I bet you will hear the difference immediately.

Try this guy.[]

That is a very impressive project. Great Job!

I started out using my paramount 300b's with the heresy II's. Personally I did not find the combination very good. Maybe a little honky, and very bass shy. They imaged very well, but the sound was just thin. The sound seemed to be coming from way back beyond the back wall of the listening room, very distant. I wired the paramounts for 4 ohms, switched to the RF-7's and never looked back. The low impedance really has not been a problem in my setup. When I switch to the 205wpc parasound amp, I get a little more control in the lower frequencies but the paramounts put out just as much. I'm probably only using the first watt of eight at my optimal listening level. That said, I would also state that the heresys were more musical, while the RF's are more analytical.

Here are some interesting comparisons. A bit dated but probably still relevant. I would definitely like to give the TJ meshplates a spin when finances are better. http://www.enjoythemusic.com/magazine/equipment/1201/300b/ The TJ's are now $309/pair.

Active Biamping - Takes the preamp output to an active crossover and then to the amps. This allows complete control of which frequencies are sent to each amp and speaker. It also makes the passive crossovers in your speakers non essential. Passive Biamping - Simply sends 2 preamp outputs to 2 different amplifiers. The passive crossovers in your speakers still do all the work. If you remove the passive crossovers from your speakers, you need to make sure that the speakers can handle the frequencies you are giving them. I sometimes passively biamp my setup. I do this to get the sweeter mids and smoother highs of the tube amps along with the bass response and speaker control of the solid state amp. If you are passively biamping with two identical amps or different channels in a multi channel amp there may not really be any difference. Both amps sound the same and each will still be amplifying the full frequency band so it won't give you any extra headroom. I think...

The S.E.X. amp would be a great way to get your feet wet. 2 Watts may or may not be enough for your listening levels, but the 8 watt 300B's on my HII's were overkill. I could have built them with the 3.5 watt 2a3's and had plenty of power. FenderBender : "Some of the bryston st amps can be had for a good price, same as the Classe (30 year warranty) as well as the older nelson Pass designs" For some warm Solid State do a search on the Nelson Pass ALEPH30. Read the reviews and then wait for one to come up for sale. $700-$900.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=091-1075 Stackable plugs.

IMO caps will 'burn in' over a period of time or change their character. I don't think it is a process that takes hundreds of hours like many folks do. I think it happens rather quickly. However, I believe that most of the brightness or harshness many people experience after replacing older or poor quality caps can be attributed to increased detail. Your ears are very accustomed to the sound of 30 year old caps and the extra information coming through the new caps is being perceived as something out of place or just wrong. 30 year old caps may be laid back or they may just be plain shot. I've never used the Sonicaps, but from all the reports I've read, they will most likely be brighter than oil caps which are known to have the more laid back sound. I'm sure you will be at least a little happier with the results in a week. Keep listening to them and let us know how it goes.

If there is nothing wrong with the speakers or amplification it is most likely the room/placement that is keeping the bass hidden. For the low frequencies your room is going to be doing most of the work. Spend some time (alot) on speaker and listening position experimentation. You will be surprised by the results. For a serious listening session I have to move everything around. The optimal placement doesn't work for normal use of the room. From The Complete guide to high-end Audio by Robert Harley (not my favorite reviwer/author but the book is chock full of common sense stuff I didn't know, not having any myself): "It has been said that a loudspeaker designer has 100% control over his product's sound above 700Hz, 50% control from 300Hz to 700Hz, and only 20% control below 300Hz. This aphorism reflects the increasing influence of the listening room on sound quality at lower and lower frequencies." Hope this helps, D

Monday night is Top Gear night. Shweeet.

I agree with inventor on this one. The RF-7 crossover upgrade is not a good first project for the DIY'er. It might sound easy just to change out the caps, but the process can be a little involving and before you know it, you might be sending Dean your disassembled crossovers anyway. [:$]

I used this stuff for polishing fret jobs on guitars. I tried it on some wood amp bases and WOW. After getting the poly flat with 400 grit wet sand paper I hit it with these. All the way down to 12,000 grit. I can barely pick them up without them slipping out of my hands. Very nice. http://www.amazon.com/MICRO-MESH-SANDING-SHEETS-INTRODUCTORY/dp/B000H6HIK2

Regardless of what the data says, this mod improved Lorenzo and Erin's systems. Period. Unless they are lying to us. If I have a choice between a system with less distortion or a system that sounds better, I will choose the latter every time. Is there really someone here who would make their system less enjoyable to improve the specs? As far as audio is concerned, I say use the science as a guide, but let your ears make the final decision.

Isn't this the basis for all mass-market audio gear? [:^)]

Already got my vote in for best gear of '09. Finished the LM3886 gainclone last night. It looks OK but it sounds fantastic. What a bargain <$120.

Parsound HCA1500A. Didn't really swap it out, just added it. I switch it with the 300b's or bi-amp. I can't decide if I'm SS or Tube.[:|] But hey, variety is the spice of life. Swapping the xicon output caps for Vcap OIMP in the Bottlehead pre really took it up a step as well.

I'm not sure how much power these things use at idle, but I turn mine off anyway. I'll switch it on when I get home and let it warm up for awhile. The 1500 runs in class A up to something like 15 watts. I probably haven't driven it past 4 with the RF-7's. It gets mighty warm on top. Make sure there is plently of room for air to circulate. Don't put it on carpet or stack anything on top. There is a thermal protection system in most of these in case of overheating.

Absolutely![*]