-
I blended the wound strings (.023,.030,.039 and .047) of an acoustic Elixir Polyweb 80/20 Bronze set with the trebles (.013 and .017) of GHS White Bronze set as an experiment on my Hofner New President and played through the George Benson and found them to sound really nice. Bass notes are clear yet full, treble strings are powerful and fat (although can get unbalanced loud if you dig in).
-
02-21-2015 02:54 PM
-
Reviving an old thread to thank Bill... Thanks!
Originally Posted by boatheelmusic
I recently picked up a Benson Hot Rod Deluxe to have an amp around the house again. As an at home player I used to have (and wish I still had) several Raezer Edge cabs (S10, S12 and Twin 8) with a Clarus, then just used modelers with studio monitors at my computer desk. It has been a long time since I played Fender with an open back cab so the sound was extremely brought, chimey, etc and not to my liking. I had played around with settings, but not really knowing what I was doing it still sounded bad to my liking. I was almost ready to throw in the towel and sell it when I came across Bill's post above with the setting he uses... Wow! That brought the tone to my liking. I haven't messed with the tube change mentioned for my Benson amp... but maybe someday if i get bored.
Great stuff as always on this forum!
-
Thanks !
It's all about increasing apparent headroom and flattening that Fender scoop in the mids by pulling down bass & treble.....IMO
-
The 12AT7 has the completely wrong plate voltage for V1. You are correct. A 5751 or even a 12AY7 for V1. A 12AT7 is a PI tube. Why Fender does this on the GB's is beyond me but probably because they only use Groove Tubes and they don't make a 5751 and a 12AY7 will cut down the volume output too much. A 12AY7 is also a very good choice for V2.
-
I have a heavily modded HRD. They basically are the same as a GB. I found a 12AT7 in V3 (PI) made it sound sterile. The HRD's were designed for a 12AX7 in V3 and you want your power tubes getting sufficient power. A real good choice for V3 is a Sovtek 12AX7LPS or if you have the bucks a Genelex Gold Lion long plate 12AX7 (the Russian one for $40.00 not the Chinese for $25.00). The long plates sound great in V1 for jazz too but if you play really loud they can go microphonic on you after a while but you can get the Sovteks for $15.00. The Gold Lions though long plate hold up very well but they are pricey. ALWAYS make sure your V3 (PI) tube has balanced triodes !!!! Very important.
-
Hi Guys, I have a Hot Rod GB myself, it sounds very nice out of the box to me.
Is modding really worth it?
Do you have some before and after audio examples?
-
If anything just replace the 12AT7 in V1 so your power tubes will last longer. It is the wrong plate voltage.
Use a 5751, 12AY7, or a 12AX7. A $15.00 fix for longevity. Don't use a Sovtek 5751. They don't sound good IMO.
The best is a NOS Jan/GE. A JJ 5751 is a good choice if you don't want to spend a lot.
-
Dirk, Originally Posted by Dirk
Vinnys been after me to modify mine.
He even sent me tubes to try.
Anyhow, I will be doing the mod and I plan on doing some before and after clips.
I bought my GB new as well and I am having a little issue with it as of late.
A couple of minutes after I fire it up, I hear a "shimmering" sort of Angelic sound for about 10 seconds, then it goes away. Occasionally, I hear it when I playing too. Weird. Do you get that with yours?
Joe D.
-
That's strange Joe, never had that.
I have some problems with tube rattling, at certain frequencies the tubes begin to rattle. Do you have that as well?
-
I don't think so, I thought my problem was tube rattle. Originally Posted by Dirk
I don't really know what tube rattle sounds like. So, maybe my problem is related to the reverb tank or something else.
Vinny (the master) told me to change out my tubes and the problem will go away.
I will be sure to give the before and after once I do the Mod.
Hey, while I have you on the line, thanks for all the work you and the other Moderators do to make this the best place on the internet, Bar None, Period, End of discussion.. I love this place and you guys make it work perfectly!
Joe D.
-
V1-JJ or NOS 5751 or Sovtek 12AX7LPS or Genelex Gold Lion LP 12AX7 gold pin
V2- Any Russian 12AY7
V3- Sovtek 12AX7LPS with BALANCED TRIODES or Gold Lion
Power Tubes- JJ 6L6 MATCHED
Bias amp to 65-70 ma. Best place IMO to get tubes is The Tube Depot. Great customer service and never a bad tube from them.
Your GB amp will go from a good jazz amp to a great jazz amp.Last edited by vinnyv1k; 09-17-2015 at 12:25 PM.
-
You will get tube rattle from a cold bias. Fender sets their bias at 60 ma for the 5 year warranty. Too cold.
-
Those tube dampners also dampen tone but do help. I don't like them. The JJ's are pretty rattle free. Go to the Eurotubes website and watch their video on how to bias a HRD. Super simple on HRD's & GB's. You will need a $15.00 volt/ohm meter if you don't have one. If you need more help pm me and I will walk you through it on the phone. Their is a bias test point on the back when you pull the back cover off and a big giant blue bias adjustment screw that you can't help but see. Easiest amp around to bias.
-
For the bias adjustment, you need a digital voltmeter, an analog volt/ohmeter won't do as well.
-
Yes I use a Fluke digital voltmeter but they are pricey. I think you can get a cheapy digital meter from Harbor Freight for under $20 that will do the job.
-
Just got my self a fender gb with a terrible tube rattle so I'm going to change the tubes (as soon as I learn how to ) I found this thread and wondered how significant are the differences in sound with all the tube mods that vinny suggested. Vinny do you mind advising? Ps I live in Italy so if you have tips for buying tubes here in Europe I would be pretty happy thanks in advance
Last edited by reefer_man; 04-11-2016 at 09:50 PM.
-
Since you are overseas go Sovtek, JJ, or Electro Harmonix. This would be a sweet combo IMO but I don't know your availability. JJ 5751 in V1, EH 12AY7 in V2, Sovtek 12AX7LPS in V3 (this tube must have balanced triodes) and
JJ 6L6 power tubes (must be matched). You can use any brand tube just remember V3 your phase inverter tube must be balanced and your power tubes matched. V1 V2 V3 are your preamp tubes. 3 preamp tubes and 2 power tubes.
Go to the Tube Depot website and Eurotubes website to get a better tube understanding. Tube rattle is a common problem In combo amps.
-
Just pull the tubes out and put new ones in :-) Originally Posted by reefer_man
Make sure you buy a matched pair. For optimal results it's best to adjust the bias, it is very easy as the HR GB has a bias-trimpot and a build-in test point. If you are lucky the new tubes are not too far off from the old ones and draw about the same bias-current and you can get away without adjusting the bias (actually, my Blues Deluxe came with fixed bias and I did some 10 years changing tubes without adjusting bias and it never harmed the amp, tubes don't come with that much variation in current draw as to harm the amp, but adjusting bias is better, also for your tone)
Here's an instruction-page with video: Hotrod Deluxe "How To" Bias Video
THERE'S HIGH VOLTAGE IN THERE THAT CAN POTENTIALLY KILL YOU. So if you feel insecure: take it to a tech.
-
Thanks everybody ! specially vinny. just to be sure that it's really a tube only problem i've uploaded a sound sample. Vinny if you can listen and confirm i only need to change tubes. i will be ordering the whole tube set today. thanks again grateful for your help
heres the sample
-
TAD is a good choice too. Probably the best Chinese tubes on the market. They are very good. Yes it sounds like you have a tube that has gone bad. If you replace your power tubes you must bias your amp. I have found around 68ma is a sweet spot for HRD/GB's. Easiest amp in the world to bias. Eurotubes or YouTube will show you how. One of the biggest causes of tube rattle is a cold bias. You might fix your problem by just getting rid of the 12AT7 in V1 and biasing your amp to 68-70 ma but I would go all new tubes if you have the money. Be very careful installing the power tubes. The index key can break off very easy. Also don't force the preamp tubes or the pins will bend. Gently rock them in. Study the tube sockets carefully to see the pin configuration.
-
Thanks again , what happens if I put the same kind of groover power tubes and change all the rest ? Do I still have to bias ?
Inviato dal mio iPhone utilizzando Tapatalk
-
Does Groover put classifications on their tube? I know some brands did and maybe still do, and MegaBoogie sells selected tubes with a color code, so if you always buy, say, orange you know they draw about the same current and you don't have to bias (because Mesa amps have fixed bias). Originally Posted by reefer_man
But if it's just the same brand, then there's no guarantee and you have to bias. But then again.. I didn't for ten years and never had a problem; so you can change them and observe: if they don't get extremely hot, if they don't red-plate and if they sound good, then you are good. But biasing is better and ensures you get the best out of the tubes and allows you to experiment to see what you like better: biased to the 'cool' or to the 'hot' side. For clean jazz you might even like a cooler bias. Is also less stress for the tubes and let's them live a little longer.
-
No but they must be the same rating. Their will be a rating number on your Groove tube power tubes or a color code. Originally Posted by reefer_man
You must must buy the same ones.
-
What eliminated tube rattle on my Hot Rod GB is installing a rubber pad in the cage of the 6L6 tubes, so that the bottom of the tubes touches the pad.
Here's my pre-amp tube configuration (all Groove Tubes available at Thomann):
v1: 12ay7
v2: 12ax7
v3: 12at7
Swapping the "ax" for "ay" and "at" did wonders for the amp's headroom.
Turning up the bias has a negative influence on the sound imo.
-
Proper bias is extremely important for a amp's performance. Too cold and the amp will sound sterile and you can get tube rattle as the tubes don't run at their proper temp. Too hot and you lose headroom and your power tubes don't last. A lot of blues players like a hot bias as it will give you that gritty hairy sound. I have done extensive testing on these HRD type amps and found 68ma to be the sweet spot. In any case you should replace your power tubes on a yearly basis. Preamp tubes last a long time. Groove Tubes are presently being made by Sovtek but that could change. They always go with the lowest bidder. The best way to buy a tube is from a specialty tube company and pay extra for lowest noise and microphonics. When I buy a tube it comes with spec data. A Groove Tube you have no idea what you are getting.
Reply With Quote
Barney Kessel sketch
Yesterday, 09:53 PM in Everything Else