speaker question

[akimball442]

I have a Marshall 1965A 4x10 slant cabinet, and I love it. I've used it in conjunction with my 5f6-A converted bassman head for a long time.

I hate to call it an upgrade, but I'd like to change the speakers. It has Celestion blue label speakers in it- I have not taken it apart in quite a while, so I'm unsure of the exact model.

The only issue is that they are not very sensitive. I'd like the cabinet to be louder. I've plugged my head into various 2x12 cabinets, and even a 1x12 cabinet that I own, which has a JBL K120 in it. They are all quite a bit louder.

What I'm wondering is whether or not anyone knows of a speaker which will sound similar to the celestions. I don't really want to drastically alter the tone of the cabinet, so if I can't, I won't. I like the tighter bottom end of the 10s, and would rather not lug around a 4x12 cabinet anyway, if I can avoid it.

Any suggestions?

FWIW, I play country and classic rock, alternating between a Telecaster with a compressor, and a Les paul for the most part. No other FX.

[pdf64]

Need to know what speakers are in there really. 10s don't tend to be very efficient.
But if you just change the bottom pair for high efficiency types it would probably help some.

[akimball442]

Thanks. You're right, pictures are worth 1000 words, especially since my memory failed. I thought for sure the speakers had blue labels, and now that I actually opened the back of the cabinet, I realize I must have been thinking of another one.

The speakers have white labels, they are G10L-35, 8 ohm, wired in series parallel for an 8 ohm cabinet:



Again, I love the sound and the size of this cabinet, I'd just like it better if it was a little bit louder.

Aaron

[pdf64]

I can't find the sensitivity rating for G10L-35, but with smallish magnets like those I doubt that they are any better than 95dB/watt, like the G10M greenback, or G10N-40 (which has a bigger magnet from the look of it, therefore should be more sensitive than the G10L pictured).
So G10L-35 may be only 93 or 94dB/watt.
I've asked Dr Decibel for the spec.
The G10 Vintage is 97dB/watt, the Gold 10 is 98dB.
Of course there are loads of eminence 10"s, but if you want to keep the same tone then sticking with celestion is likely to be the best chance of keeping that tone.
And as the first go, just replace the bottom pair - it may be enough for a sufficient volume boost and you'll keep the tone of the top pair.
As magnet size tends to affect the tone as well as the sensitivity - more/tighter bass and a more cutting top end.

[J M Fahey]

You were spot-on.
G10L35 are the least efficient of "serious" Celestions, 94dB .
Sound is not bad, though.
Problem is, most 10's, including the new Tube 10 are not much louder.
Yours are somewhat equivalent to Jensen MOD 10-50, which sport the same magnet and voice coil, for 95.8dB efficiency, slightly better because of modern construction.
You could also use 4 MOD 10-70, which have a significantly larger magnet and voice coil, for 98.2 dB, quite an improvement, both in sensitivity and body.
They claim to be "British voiced" compared to other Jensens, and the price is good.
Another option would be to cut a new front board for two 12" speakers of your choice, Celestions welcome.

[akimball442]

Interesting, thanks for the replies!


I do love the cabinet, the sound is unique. In fact, it got me into some trouble with a couple of builds that I thought sounded fantastic, then they sounded lousy with other cabinets.

I may just grab a set of four of something, to give them a shot. The Mods are definitely affordable.

I never thought about doing 2 12's... that's another thought.

I'm thinking I'll stick the 4 Celestions into my Ampeg VT-40, as it's CTS junkers have disintegrated.

[d95err]

Eminence has several 10's with an efficiency of 100dB. The Red Fang 10 even at 102dB. I have no idea what they sound like though.

[pdf64]

Dr Decibel advises that the G10L-35 is 95dB/watt.
Rather than replace the speakers to get another 3dB, how about beefing up the amp to a 4 x 6L6 type, as the speaker has plenty of power handling?
That should give you another 3dB.

[akimball442]

Dr Decibel advises that the G10L-35 is 95dB/watt.
Rather than replace the speakers to get another 3dB, how about beefing up the amp to a 4 x 6L6 type, as the speaker has plenty of power handling?
That should give you another 3dB.

I'm still on the fence about actually changing them. I played it today, and it just sounds so good.

In terms of 100W amps, you read my mind. I normally use a reworked bassman head, which is more or less a standard 5F6-A circuit in one channel, and an additional simple tweed (volume/tone) in the other channel. I love this amp...


So I have a 1968 Twin, which has been my primary gigging amp for a long time, because it's loud, and reliable. It's a very early silverface with the stripes on the faceplate and the AB763 circuit.

I never use the tremolo, so I'm thinking of converting a channel of that to the bassman style preamp, it'd be simple enough because I'd have the extra tube from the tremolo to add the cathode follower. Actually I think the tweed Twin was pretty much a 4 6L6 bassman anyway. I can use the holes for the trem pots for master and presence. Add channel switching..... Oh no, another Frankenstein. I never planned to violate this amp... But a channel switcher with a blackface channel and a tweed bassman/twin channel....oooooo.....

I actually built a 50W version of that for one of my band mates out of a pro reverb, and converted it to a head. He loves it. Mine would have reverb....

[Steve Conner]

I wouldn't change the speakers, the cork-sniffing brigade seem to rate those ones highly

[pdf64]

'So I have a 1968 Twin, which has been my primary gigging amp for a long time, because it's loud, and reliable. It's a very early silverface with the stripes on the faceplate and the AB763 circuit....But a channel switcher with a blackface channel and a tweed bassman/twin channel....oooooo.....
'
I'll have to send the vintage amp police over your way if you carry out this evil plan - don't make me do it!
How about a Weber kit (eg 6M100, 6A80 Head or Heather) - they're running a 10% discount currently?

[akimball442]

'So I have a 1968 Twin, which has been my primary gigging amp for a long time, because it's loud, and reliable. It's a very early silverface with the stripes on the faceplate and the AB763 circuit....But a channel switcher with a blackface channel and a tweed bassman/twin channel....oooooo.....
'
I'll have to send the vintage amp police over your way if you carry out this evil plan - don't make me do it!
How about a Weber kit (eg 6M100, 6A80 Head or Heather) - they're running a 10% discount currently?

Well, I have kind of two views on it. My AB165 bassman was a VERY early silverface, with the blue and silver sparkle grill cloth and the aluminum 'drip edge.' I don't really care. I'd never drill a hole in it, and I always keep the old parts in a zip lock bag, ready to be converted back if need be. I even remove the wire if it's going to be too short, and save that.

Fender amps are cheap, and easy to mod. Buying a kit is expensive, and I'm cheap. I'd never spend $1000 on an amplifier. I'll spend $200 on a silverface on craigslist, that's 'blown.' Out of probably ten that I've purchased that way, only one had a bad transformer. Surprise, surprise, the fuse was wrapped in aluminum foil... original problem was that one of the filament wires was shorted to ground. The others were all very simple problems, ranging from burned resistors and bad caps, to just a bad tube. The Twin that is the topic of this discussion was actually a gift from one of my band mates for fixing one of his Fenders that he liked better. So free to me. I swapped out the crappy Utah speakers and have gigged with it for a few years now.

OT: I'm an avid vintage car enthusiast. Particularly Mercedes-Benz. I own four. If I can improve upon something that's a chronic problem (which most 30+ year old cars have) I'll do it, regardless of it's potential effect on the value. We engineers are evil people like that....I own them because I enjoy working on them, and I enjoy driving them. They were engineered and built to be driven, not to sit in a museum.

Back on topic, I feel the same way about my amps. They don't sit around collecting dust. I have a few neat things that, while they work, are more or less conversation pieces, but most of them I'll actually use. I want to like what I hear coming out of the speakers. My SF bassman doesn't sound like a SF bassman, or a true 5f6-A, and it doesn't sound like a Marshall. It sounds like my amp, and I like it. It can all be reversed, and I do not do half-assed work. No damage was done. If someone offered me top dollar for it, I'd probably still keep it, because I like it.

On the other hand, I can see why people would get upset about modifying vintage equipment, but it's not like I'm routing a center pickup cavity in a 1952 Telecaster (which I have seen done, and it's painful). But how much is it really worth, and of what significance is it to the vintage collector when it's not for sale. I suppose once I'm gone, someone might open it up and get upset with me, haha.

My parents did everything they could for me, and sacrificed a lot for my sister and I, but we never had a lot. I always had to learn to get by with what I already had. I could not afford a Marshall. If I wanted one, I had to build one. It's stuck with me after all this time, even though thankfully, I'm in a much better position now.

I hope this didn't come across as a rant, because that's not my intention at all, it's just one of those interesting discussions. People get very attached to, and up in arms about the vintage and collectible value of a lot of this old equipment. To me, they're just amps. Excellent amps, which with some tweaking, have put a smile on my face every weekend, and extra money in my pocket.

I think the best payoff for me is when someone comes up during a break to ask me what pedal I'm hiding, because they would like to buy one. I've had that happen a few times. Typically, I just have a compressor between my Tele and the amp, and that's it. The tone comes from my instrument, and my amplifier.

[pdf64]

Absolutely, I'm with you 100% on this, pragmatism has to rule, though I do have a slight feeling of remorse when opening up a pristine 60s amp and replacing the noisy resistors and dead electrolytics.
And being able to pick up blown vintage amps for $200 would certainly make modding, rather than a new build, much more pragmatic. The likihood of that kind of find in the UK these days is pretty low, everyone seems to have wised up as values have risen.

[Steve Conner]

Well, except for those 70s aluminium panel Selmers.

My rule would be, if you have a vintage amp sitting there that doesn't do what you want, can you sell it for enough to buy an amp that does do what you want?

If the answer is no, then mod away. The market has spoken.

Broken silverface Twins turn up on Ebay UK now and again for reasonable prices. Just watch out for the UL ones.