Grounded Grid Preamp

[ray bronk]

Hi Guys,

Well, considering the GGP preamp to build or maybe the one from Bottlehead. Also considering just buying the Symphony Plus and be done with it. I'm not to familiar with the "tube sound." But from what I have read so far, it seems like the 12A*7 family is fairly neutral and dynamic in its sound character. That 12B4 sounds even better. I don't have the skills, and because I am a person who is blind, can't see the pics. I can solder. So I'd have to have something built up for me. Anyhow, before I tackle getting anyone of these prees, I thought I'd get some of your thoughts. Bruce's GGP doesn't have a tube rectifier. Supposedly, that's suppose to make a big difference.

Thank you for any thoughts. What improvements can I make on that preamp or some of the others I have mentioned.

Much appreciated,
Ray

[Gordy]

Hello Ray,

I'm not sure that there is actually a true 'tube sound'. Every preamp seems to be a little different to the next.

Although I have not heard the Grounded Grid preamp from Transcendent, I have heard good reports from those that have heard it. It also seems good value at $799 factory built, so that may be your best bet.

[pchw]

Hi Ray,

Like Gordy says, every preamp sounds a little different from the other, SS or tube. I have a factory wired grounded grid and a scratch build. The difference is on the power supply, the scratch build uses tube rectification instead of SS diode on the B+ side. Guess what, in A/B comparison, they do sound slightly different!!! The GG sound is on the natural and transparent side, very different from my Marantz 7C clone which has this kind of "tubey" sound most people talk about. I hope this will help. If not, feel free to ask.

[ray bronk]

Hi Fred,

That sounds really good. I have seen preamps out there with the 12A*7 configuration. It also has a tube rectification. Supposedly, the tube sounds better than solidstate rectivication. Don't know. I guess I'll just have to get one and see. Did you do any mods to your GGP?

Ray

[pchw]

Hi Ray,

It can be the tube rectification, or it can be because of I built it :-) I do like the tube rectifier (6x4) version more. I neither used any exotic parts nor modified the original design. The differences are rather minor:
1. Tube rectification vs SS
2. My B+ transformer was from an old Eico tuner which also provide the filament winding.
3. My heater supply is 6.3VDC unregulated instead of regulated 12 as in the original schematic!!
4. The output caps are different brand. Factory came with Solen, I used CDE.
5. The factory build also has the optional attenuator, and my scratch build has a cheap carbon pot. The attenuator is a clear winner here. It is much more balanced at low volume!! My El Cheapo pot probably has a wrong log curve. It has too much output in the initial turn.
6. There is no source selector in my scratch build. It has only one input!!

Other members said John Broskie's Aikido sounded even better, but I haven't finish mine. So, I really can't say one way or the other for the moment.

Cheers,

[ray bronk]

Hi Fred,

Thanks for the info. So the GGP sounds better than your "scratch" unit? You used DCE caps? Why? Just curious. If you go up to the Audiogon, under tubes, this tuy has a Symphony V2R for 448 bucks with remote. Now, he just uses the Elps pot, with Phillips caps. He uses a 6X4 rectifier. That was why I was asking about the differences in rectification. Bottlehead makes there same one, with I think tube rectification and some other stuff too. So that's where I am. Unfortunately, I will have to have someone initially build the preamp. Why don't you just get another stepped atenuator like the one in the GGP and put it in your "scratch" unit? It will make things a bit closer in comparison.

Ray.

[pchw]

Hi Ray,

Technically speaking, both the factory wired and my scratch build are Grounded Grid Preamp. They have virtually the same schematic with the difference I mentioned previously. I prefer my scratch build's to the factory wired for a slightly larger sound stage and slightly lower noise floor. The differences are very subtle. I wouldn't notice that if I didn't do A/B comparison. Quite frankly, I can't say for sure it is the 6x4 a major factor. The output caps and the carbon pot can also contribute the variation. Why I use the CDE cap? Don't laugh, when I ordered the parts from digikey, I happened to see that one fit my wallet :-) It is twice as expensive as the Solen that the factory used, but nothing exotic; however, the construction definitely looks better than the Solen - the size is almost twice as big either :-) Seriously, I believe a good SS rectification is just as good. For example, the B- of my scratch build is SS rectification.

I didn't audition to the V2R, but I did audition another preamp from Audio Experience. I suspect that could be the same as the V2R without the remote. That AE preamp also used 3 12AX7's. The circuitry was very very similar to most of the Marantz 7c clone such as mine. It does have the "tubey" sound and is less transparent/natural than the GG. Comparing the 2, the GG definitely sound more lively and more dynamic. Assuming the V2R is a remote version of what I auditioned, it is not bad especially for that money with the remote feature and ready to play. If you can find some friend to help you to build from the kit, go for the GG, that will be my choice.

[ray bronk]

Hi Fred,

Have you looked or heard the Bottlehead Foreplay 3?

The Sonic Experience seems interesting. Maybe, the GGP quality of Build is better.

Ray

[pchw]

Hi Ray,

I didn't listen to the Bottlehead but have seen good reviews from various message boards. If I remember correctly, the Foreplay will sound even better with the ccs boards.

[ray bronk]

Hi Fred,

I was thinking about that idea too. It comes with a 28 Page manual. So I presume it would tell you how to install it.Not to expensive either.

Ray