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Topic: 4 or 8 ohm recone for 15" Altec 418 to use in Twin Reverb? |
G. Robertson
From:
California, USA
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Posted 16 Feb 2015 3:01 pm |
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I have an old blown 15" Altec 418 that I would like to use with an old Fender Twin Reverb which has a 4 ohm output. Orange County Speaker does a stock spec 8 ohm recone but has no 4 ohm voice coils available. Has anyone ever had an Altec 418 reconed to 4 ohms? If so, I'd love to know where to get it done.
Also, knowing a higher load (8 ohm speaker on a 4 ohm amplifier output) is not much of an issue other than reducing output power, what has been your experience in terms of sound quality running an 8 ohm speaker on a tube amplifier with a 4 ohm output? Should I just go with the stock 8 ohm recone? |
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Cartwright Thompson
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Posted 16 Feb 2015 3:33 pm
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Recone it to 8 ohms. Find a good amp tech and have him setup your amp with two 6550's. Very minor mods ( just beefier screen resistors) and you can always go back to four 6L6's without changing anything. When you use two power tubes in a four tube amp the output impedance is doubled, i.e. The Twin wants to "see" 8 ohms instead of 4.
You'll get about 70 watts and it will sound great, you probably won't notice any loss of power. 418's are great speakers. |
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Dave Zirbel
From:
Sebastopol, CA USA
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Posted 17 Feb 2015 5:56 am
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I would recommend having Great Plains Audio to do the recone.
From the website:
"Great Plains Audio was formed in 1998 after the closing of the Altec Lansing factory in Oklahoma City. It was clear to Bill Hanuschak, who worked for them from 1980 until they closed, that there would be a need for someone to continue the maintenance of the large number of Altec acoustic products in use around the world. So, he went to EVI/Telex, who had purchased Altec Lansing, with a plan to purchase all of the tooling, drawings, and equipment Altec used to build and service their loudspeakers, and to become their authorized service center for all of the Altec Lansing products that were still under warranty at that time. In addition, GPA assumed repair duties for all of the older, classic products that had served Altec’s customers since it's inception with the parts manufactured from the original Altec tooling. "
_________________
Dave Zirbel-
Sierra S-10 (Built by Ross Shafer),ZB, Fender 400 guitars, various tube and SS amps |
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G. Robertson
From:
California, USA
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Posted 17 Feb 2015 10:21 am
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Thanks for the tip, Cartwright. I had forgotten about pulling a pair of the power tubes to double the output impedance. I'll try that with the 6L6s first and see how it suits me once I get the re-cone done. I'm sure it'll still be plenty loud with headroom running two tubes. The re-bias/screen resistor change to use 6550s is intriguing. I've done that with EL84s for use with my Tele but never had an amp running 6550s.
And thanks for the Great Plains recommendation, Dave. I've heard great things about them. |
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Bill Hatcher
From:
Atlanta Ga. USA
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Posted 17 Feb 2015 10:41 am
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| maybe my fav speakers the old white frame altecs in 12" and 15". problem is that when you recone them...they are no longer as good as the original altecs. you need to really investigate what is being used for the voice coil and most important for the paper cone. the altec has a very thin paper cone. i am not a speaker guru, but i have to believe that the thin cone aids in the fast response and the wonderful upper freqs these have. same thing is true with reconed JBL stuff. if the parts are not exact to spec then they are no better than a cheap speaker. there was a time when EV owned altec. i had some recone guys who had access to some altec voice coils that were of higher wattage, but you could save the original altec paper if it was still in good shape. good luck. using an 8ohm with a 4ohm output will be no problem at all. |
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Jerry Hedge
From:
Norwood Ohio U.S.A.
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Posted 18 Feb 2015 8:16 pm
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| Dave Zirbel wrote: |
I would recommend having Great Plains Audio to do the recone.
From the website:
"Great Plains Audio was formed in 1998 after the closing of the Altec Lansing factory in Oklahoma City. It was clear to Bill Hanuschak, who worked for them from 1980 until they closed, that there would be a need for someone to continue the maintenance of the large number of Altec acoustic products in use around the world. So, he went to EVI/Telex, who had purchased Altec Lansing, with a plan to purchase all of the tooling, drawings, and equipment Altec used to build and service their loudspeakers, and to become their authorized service center for all of the Altec Lansing products that were still under warranty at that time. In addition, GPA assumed repair duties for all of the older, classic products that had served Altec’s customers since it's inception with the parts manufactured from the original Altec tooling. " |
The Great Plains Audio products are exact replicas of the original Altec products. The Raw materials are sourced from the original suppliers. |
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