Ar9Jim

Welcome to CS.. Enjoy..

Welcome Vin.. Great gear you have. Thanks for sharing the story and pics..

Thanks for sharing. Very interesting. Also from a time when everything ran on tube amps.. If you told listeners they are some new high tech product they would likely believe you.. Interesting a few years later man would land on the moon. A great time for American engineering and still impressive in 2016..

I see. Yeah the design make everything else compromise in order to work with it. Think there are some huge chances to add value with some of the kits.. Nice to spend the money on great parts and add your own time. Your not rushed like a line worker trying to make rate for the day.. Had 4 passive crossovers that I rebuilt. 2 of them had connection points that had been missed(by the maker) during solder completely, and were connected by the lead wrapped around a post only.. OCCD prevents this type of mistake.

Onelasttime, You make many good points that are certainly fact as to the lifespans of materials and things.. We all have our reasons though for approaches to vintage gear and the desire to own it.. I restore old tube amps using the vintage circuit designs but with modern parts. My goal is not to bring back something that will never be, but to use the vintage design and optimize it with the low noise, closer tolerance, better imho parts of today.. Many times its the design and designers work that we want to hear. IIRC there are only 3 basic amp circuits (correct me if I'm wrong anyone) that all are versions or tweaks of.. Its the same with speakers. Although the materials may fail and need replacement at considerable cost, the design lives on. Companies change designs often and not always for the better.. Many times the best work from companies are in their past and the new products are not as good.. In the case of my tube amps, I could buy a China made tube amp that may or may not sound just as good, for the same money as my restomod vintage amps.. But these are the work of Americans like our grandfathers and American designs in many cases.. There is some romance in there and some pride in history, that can cause us to overpay to pristine examples, but the same can be said for anything especially cars.. As far as collector cars they were not that good when new, compared to today's cars but people restore them and enjoy them none the less.. I would like to have some modern American tube amps but this close to retirement I'll stick with vintage that are easier to afford.. It's fun to restore old amps and when listener comments on the wonderful sound, its awesome to say " it was made in 1962 USA" Most cannot believe it.. If you enjoy playing with vintage gear and can repair/restore yourself that's great.. If you have to pay a shop to do it for you it would be tough to justify imho..

Just curious, It seemed like the quality was there and you feed more power. When you say you cant get the "sound out of these that you want " are you speaking in terms of volume level? The design is interesting, keeping the woofer near the floor/back wall intersection, and at the same time moving the other drivers forward away from the wall.. The sides of the cabinets make big reflective areas and with the side firing woofers was that a problem? Kind of has the woofers boxed in on 3 sides between the cabinets and the back wall.

Very nice.. The kind of wife that likes gear and wants to buy amps, is a good women.. Is that a kitten at the left side of the picture. The one about to get shot across the room, when that JBL fires up..

Very nice work. Thanks for sharing..

It is an error. The polarity is reversed on the output of the low frequency amp on the left channel.. Good catch..

Curious as to how you like the bigger amp on those speakers. Should be a great thing..

Yes, the originals from around 1979.. I remember when ported speakers were the hot item and acoustic suspension seemed a bit power hungry and inefficient, maybe obsolete.. I found them to be accurate down deep and worth it to feed them.. Decades later the Carver subs seem like acoustic suspension taken to a new level and side firing drivers seem to be on the rise.. Again..

Very nice speakers. You can see AR in the design. Acoustic suspension. narrow front baffle, side firing woofer near the floor.. Give them a bit of time and your wife may learn to love them.. Thanks for sharing. My kind of speaker.. Dave, do you know where Tim Holl went after AR? Just wondering if he did anything cool after the AR9..

The flow chart by Dave is excellent for the passive Biamp setups. See the one labeled standard for an example of horizontal and the vertical example is a great chart for your other option with your gear on hand.. Zumbini post an excellent example of active setup (his own). Much more technical and requires some geekiness to get right (in a good way).. Passive is a good way to start.

Ok so your 2 sets of speaker binding post are tied together with a jumper of some sort for use when your not using a bi-amp set-up (2amps). The jumpers need to be removed. This type of bi-amp setup is easy. It is a passive bi-amp setup. It is using your speakers internal passive crossovers, as opposed to an active bi-amp setup using an active electronic crossover before the amps to narrow the band width that the amps operate within before feeding drivers.. With the passive setup you will feed both of the amps the same full range signal. Carver Preamps usually have 2 pairs of main out jacks and can make this easy.. Then you wire one amp to the woofer or bass binding post and the other amp to the upper end or mids/highs binding post.. This is called horizontal bi amp.. You can also do a vertical bi amp with the setup you have. That would be using one amp for each channel but in stereo.. You have one channel feed the lows and the other channel of the same amp run the highs. One amp on each channel.. These would be your options for passive bi amp that I have played with, both horizontal and vertical.. Active is another subject entirely..

Hi Trav.. You have a huge choice of speakers.. The vintage speakers can be a great value although many times they need some restoration.. Many guys around here have Carver speakers, Many also enjoy Polk Audio especially the SDA series.. Myself, I have been an AR guy and there are several others around.. If you find speakers set up for bi-amp (4 binding post each speaker) then you have more options for changing your system around and trying new things.. You can also get great subwoofer/sat systems.. I prefer large cabinet volume, acoustic suspension, floorstanding types with lots of power on them, but I'm kind of old and that's how it was done back in the day.. Carver made the big power we were after at a price we could conceive and own someday.. If you have any vintage hi fi shops in your area, you may find some speakers to try.. Enjoy the search, it can be a lot of fun!! I suggest reading reviews of the most awesome speakers you have heard of, that were somewhat mass produced.. Flatter frequency response in the bass region cost money in general, but is worth paying for imno.. Shipping can be costly, but I used Uship before and it went well and didn't break the bank (read driver feedback before choosing). Sometimes electronics from dry climate areas can be in better condition than humid salty areas.. Guess that's all I've got.. Think of the ones you dreamed of in your youth and make that dream a reality.. Not sure it gets any better than that.. Hope this helps.. Enjoy..

Welcome Armstrong.. Enjoy..

Very nice. Like the port with the flared exit.. Back in the day we only had PVC pipe. Thanks for sharing..

I understand that the frequencies, that the impedance dips occur, have a huge impact on how difficult the load will be for an amp.. Like the Kappa 9s that are known for dips in impedance at frequencies that give some amps trouble. Agree much more than just nominal impedance involved but its a place of reference and it gave us something to talk about..

I'm with you all the way up to this point Lighter load from a resistance viewpoint.. Working harder because of increased current demand into a less resistive load.. Increasing the resistance of the load makes (the typical voltage source) amp work less hard. I think you're saying the more reactive the load, the less its overall impedance is due to resistance? And that highly reactive loads, especially low impedance, can be very difficult for an amp? I'd certainly agree with that. But everything is frequency dependent, including how much the amp cares. Fill, I apologize if my terms were improper and confusing. My basic point that I attempted to make is this. The lower the ohm rating of a speaker, the less resistance the amp will see in general, I understand that the impedance changes at different frequencies, but in general, a lower impedance speaker say 4 ohms vs 8 ohms will be a more difficult load for an amp.. The lower resistance of the load causes the current demand from the amp to increase. Just basics, don't tell me I even have that wrong.. Lol.

Servicing is better sooner than later! At this age they all need some kind of TLC. The TFM-42 I'm working on now ran pretty good at first glance, but on recapping I found two caps that had dried out so bad that they might as well have not even been there: a VAS decoupling cap and the -11.4V supply filter. Half of the rest of the small caps were merely in poor shape, par for the course... Jim, I don't understand when you say a lower impedance speaker presents a lighter load to the amp, or how a lighter load makes the amp work harder? Lighter load from a resistance viewpoint.. Working harder because of increased current demand into a less resistive load..

Hard to imagine that TFM-42 having issues and not providing enough current to at least 99 % of speakers IMHO.. Has the amp been serviced yet? Could be an issue if not, and putting under heavy load.. My basic understanding for sake of conversation, is that the lower impedance speakers show a load similar to a smaller rated resistor, or closer to a short circuit. This causes the amp to need the capacity to flow more current to carry the load (actually a lighter load but makes the amp work harder). Most of my experience has been with AR9s and 90s. They are 4 way 5 drivers each. 3.6 ohms.. Ran a couple different pairs over many years with M400s, M500T M1.0Ts both stock and MkII, TFM 25, Silver 7Ts and several tube amps that should have been poor match but worked great. Never had a problem.. With a stock M500T I can tell when the amp runs out of gas, the power meter needles become reluctant to move higher and the volume doesn't increase, I never leave it that way, but always turn it down, back to where the amp can be comfortable with the load, never leave it running on the ragged edge of its capacity, back it down and give it some room to work. Guys running un serviced amps this hard will find trouble at some point. But if the 42 is in good shape and the speakers are not being abused by the owner with a clipped amp or excessive power and overheating, then I still bet on the crossovers bleeding signals and taking out the fragile higher end drivers..

Welcome Kevin, to all things Carver and other sweet gear too. Enjoy..

Welcome hifidoctor.. I suspect it is normal to pick up noise on most amps when the inputs are not connected and the amps are under power.. It is always recommended to have the preamp connected and under power before turning on the amps, and when shutting down, turn the amps off before the preamp.. Open inputs on an amp connected to speakers and under power can be a bad thing and very noisy.. When you say audio hum, I am assuming the sound is coming through speakers and not transformer hum from the amp itself?

Welcome to CS Ken! Enjoy.. More responses to your question with come in as the hours go by. The techs here are second to none..

Hi Carlo, Welcome to CS. There are people here that will have your answer. Many Polk fans here as well. Someone will have an answer to your question shortly. Enjoy.